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Diffstat (limited to 'sql/item.h')
| -rw-r--r-- | sql/item.h | 7593 |
1 files changed, 7593 insertions, 0 deletions
diff --git a/sql/item.h b/sql/item.h new file mode 100644 index 00000000..2720ddde --- /dev/null +++ b/sql/item.h @@ -0,0 +1,7593 @@ +#ifndef SQL_ITEM_INCLUDED +#define SQL_ITEM_INCLUDED + +/* Copyright (c) 2000, 2017, Oracle and/or its affiliates. + Copyright (c) 2009, 2021, MariaDB Corporation. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; version 2 of the License. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA */ + + +#ifdef USE_PRAGMA_INTERFACE +#pragma interface /* gcc class implementation */ +#endif + +#include "sql_priv.h" /* STRING_BUFFER_USUAL_SIZE */ +#include "unireg.h" +#include "sql_const.h" /* RAND_TABLE_BIT, MAX_FIELD_NAME */ +#include "field.h" /* Derivation */ +#include "sql_type.h" +#include "sql_time.h" +#include "mem_root_array.h" + +C_MODE_START +#include <ma_dyncol.h> + +/* + A prototype for a C-compatible structure to store a value of any data type. + Currently it has to stay in /sql, as it depends on String and my_decimal. + We'll do the following changes: + 1. add pure C "struct st_string" and "struct st_my_decimal" + 2. change type of m_string to struct st_string and move inside the union + 3. change type of m_decmal to struct st_my_decimal and move inside the union + 4. move the definition to some file in /include +*/ +struct st_value +{ + enum enum_dynamic_column_type m_type; + union + { + longlong m_longlong; + double m_double; + MYSQL_TIME m_time; + } value; + String m_string; + my_decimal m_decimal; +}; + +C_MODE_END + + +class Value: public st_value +{ +public: + bool is_null() const { return m_type == DYN_COL_NULL; } + bool is_longlong() const + { + return m_type == DYN_COL_UINT || m_type == DYN_COL_INT; + } + bool is_double() const { return m_type == DYN_COL_DOUBLE; } + bool is_temporal() const { return m_type == DYN_COL_DATETIME; } + bool is_string() const { return m_type == DYN_COL_STRING; } + bool is_decimal() const { return m_type == DYN_COL_DECIMAL; } +}; + + +template<size_t buffer_size> +class ValueBuffer: public Value +{ + char buffer[buffer_size]; + void reset_buffer() + { + m_string.set(buffer, buffer_size, &my_charset_bin); + } +public: + ValueBuffer() + { + reset_buffer(); + } +}; + + +#ifdef DBUG_OFF +static inline const char *dbug_print_item(Item *item) { return NULL; } +#else +const char *dbug_print_item(Item *item); +#endif + +class Virtual_tmp_table; +class sp_head; +class Protocol; +struct TABLE_LIST; +void item_init(void); /* Init item functions */ +class Item_basic_value; +class Item_result_field; +class Item_field; +class Item_ref; +class Item_param; +class user_var_entry; +class JOIN; +struct KEY_FIELD; +struct SARGABLE_PARAM; +class RANGE_OPT_PARAM; +class SEL_TREE; +class With_sum_func_cache; + +enum precedence { + LOWEST_PRECEDENCE, + ASSIGN_PRECEDENCE, // := + OR_PRECEDENCE, // OR, || (unless PIPES_AS_CONCAT) + XOR_PRECEDENCE, // XOR + AND_PRECEDENCE, // AND, && + NOT_PRECEDENCE, // NOT (unless HIGH_NOT_PRECEDENCE) + CMP_PRECEDENCE, // =, <=>, >=, >, <=, <, <>, !=, IS + BETWEEN_PRECEDENCE, // BETWEEN + IN_PRECEDENCE, // IN, LIKE, REGEXP + BITOR_PRECEDENCE, // | + BITAND_PRECEDENCE, // & + SHIFT_PRECEDENCE, // <<, >> + INTERVAL_PRECEDENCE, // first argument in +INTERVAL + ADD_PRECEDENCE, // +, - + MUL_PRECEDENCE, // *, /, DIV, %, MOD + BITXOR_PRECEDENCE, // ^ + PIPES_PRECEDENCE, // || (if PIPES_AS_CONCAT) + NEG_PRECEDENCE, // unary -, ~, !, NOT (if HIGH_NOT_PRECEDENCE) + COLLATE_PRECEDENCE, // BINARY, COLLATE + DEFAULT_PRECEDENCE, + HIGHEST_PRECEDENCE +}; + +bool mark_unsupported_function(const char *where, void *store, uint result); + +/* convenience helper for mark_unsupported_function() above */ +bool mark_unsupported_function(const char *w1, const char *w2, + void *store, uint result); + +/* Bits for the split_sum_func() function */ +#define SPLIT_SUM_SKIP_REGISTERED 1 /* Skip registered funcs */ +#define SPLIT_SUM_SELECT 2 /* SELECT item; Split all parts */ + + +#define NO_EXTRACTION_FL (1 << 6) +#define FULL_EXTRACTION_FL (1 << 7) +#define DELETION_FL (1 << 8) +#define IMMUTABLE_FL (1 << 9) +#define SUBSTITUTION_FL (1 << 10) +#define EXTRACTION_MASK \ + (NO_EXTRACTION_FL | FULL_EXTRACTION_FL | DELETION_FL | IMMUTABLE_FL) + +extern const char *item_empty_name; + +void dummy_error_processor(THD *thd, void *data); + +void view_error_processor(THD *thd, void *data); + +/* + Instances of Name_resolution_context store the information necessary for + name resolution of Items and other context analysis of a query made in + fix_fields(). + + This structure is a part of SELECT_LEX, a pointer to this structure is + assigned when an item is created (which happens mostly during parsing + (sql_yacc.yy)), but the structure itself will be initialized after parsing + is complete + + TODO: move subquery of INSERT ... SELECT and CREATE ... SELECT to + separate SELECT_LEX which allow to remove tricks of changing this + structure before and after INSERT/CREATE and its SELECT to make correct + field name resolution. +*/ +struct Name_resolution_context: Sql_alloc +{ + /* + The name resolution context to search in when an Item cannot be + resolved in this context (the context of an outer select) + */ + Name_resolution_context *outer_context; + + /* + List of tables used to resolve the items of this context. Usually these + are tables from the FROM clause of SELECT statement. The exceptions are + INSERT ... SELECT and CREATE ... SELECT statements, where SELECT + subquery is not moved to a separate SELECT_LEX. For these types of + statements we have to change this member dynamically to ensure correct + name resolution of different parts of the statement. + */ + TABLE_LIST *table_list; + /* + In most cases the two table references below replace 'table_list' above + for the purpose of name resolution. The first and last name resolution + table references allow us to search only in a sub-tree of the nested + join tree in a FROM clause. This is needed for NATURAL JOIN, JOIN ... USING + and JOIN ... ON. + */ + TABLE_LIST *first_name_resolution_table; + /* + Last table to search in the list of leaf table references that begins + with first_name_resolution_table. + */ + TABLE_LIST *last_name_resolution_table; + + /* Cache first_name_resolution_table in setup_natural_join_row_types */ + TABLE_LIST *natural_join_first_table; + /* + SELECT_LEX item belong to, in case of merged VIEW it can differ from + SELECT_LEX where item was created, so we can't use table_list/field_list + from there + */ + st_select_lex *select_lex; + + /* + Processor of errors caused during Item name resolving, now used only to + hide underlying tables in errors about views (i.e. it substitute some + errors for views) + */ + void (*error_processor)(THD *, void *); + void *error_processor_data; + + /* + When TRUE items are resolved in this context both against the + SELECT list and this->table_list. If FALSE, items are resolved + only against this->table_list. + */ + bool resolve_in_select_list; + + /* + Security context of this name resolution context. It's used for views + and is non-zero only if the view is defined with SQL SECURITY DEFINER. + */ + Security_context *security_ctx; + + Name_resolution_context() + :outer_context(0), table_list(0), select_lex(0), + error_processor_data(0), + security_ctx(0) + {} + + void init() + { + resolve_in_select_list= FALSE; + error_processor= &dummy_error_processor; + first_name_resolution_table= NULL; + last_name_resolution_table= NULL; + } + + void resolve_in_table_list_only(TABLE_LIST *tables) + { + table_list= first_name_resolution_table= tables; + resolve_in_select_list= FALSE; + } + + void process_error(THD *thd) + { + (*error_processor)(thd, error_processor_data); + } + st_select_lex *outer_select() + { + return (outer_context ? + outer_context->select_lex : + NULL); + } +}; + + +/* + Store and restore the current state of a name resolution context. +*/ + +class Name_resolution_context_state +{ +private: + TABLE_LIST *save_table_list; + TABLE_LIST *save_first_name_resolution_table; + TABLE_LIST *save_next_name_resolution_table; + bool save_resolve_in_select_list; + TABLE_LIST *save_next_local; + +public: + Name_resolution_context_state() {} /* Remove gcc warning */ + +public: + /* Save the state of a name resolution context. */ + void save_state(Name_resolution_context *context, TABLE_LIST *table_list) + { + save_table_list= context->table_list; + save_first_name_resolution_table= context->first_name_resolution_table; + save_resolve_in_select_list= context->resolve_in_select_list; + save_next_local= table_list->next_local; + save_next_name_resolution_table= table_list->next_name_resolution_table; + } + + /* Restore a name resolution context from saved state. */ + void restore_state(Name_resolution_context *context, TABLE_LIST *table_list) + { + table_list->next_local= save_next_local; + table_list->next_name_resolution_table= save_next_name_resolution_table; + context->table_list= save_table_list; + context->first_name_resolution_table= save_first_name_resolution_table; + context->resolve_in_select_list= save_resolve_in_select_list; + } + + TABLE_LIST *get_first_name_resolution_table() + { + return save_first_name_resolution_table; + } +}; + +class Name_resolution_context_backup +{ + Name_resolution_context &ctx; + TABLE_LIST &table_list; + table_map save_map; + Name_resolution_context_state ctx_state; + +public: + Name_resolution_context_backup(Name_resolution_context &_ctx, TABLE_LIST &_table_list) + : ctx(_ctx), table_list(_table_list), save_map(_table_list.map) + { + ctx_state.save_state(&ctx, &table_list); + ctx.table_list= &table_list; + ctx.first_name_resolution_table= &table_list; + } + ~Name_resolution_context_backup() + { + ctx_state.restore_state(&ctx, &table_list); + table_list.map= save_map; + } +}; + + +/* + This enum is used to report information about monotonicity of function + represented by Item* tree. + Monotonicity is defined only for Item* trees that represent table + partitioning expressions (i.e. have no subselects/user vars/PS parameters + etc etc). An Item* tree is assumed to have the same monotonicity properties + as its corresponding function F: + + [signed] longlong F(field1, field2, ...) { + put values of field_i into table record buffer; + return item->val_int(); + } + + NOTE + At the moment function monotonicity is not well defined (and so may be + incorrect) for Item trees with parameters/return types that are different + from INT_RESULT, may be NULL, or are unsigned. + It will be possible to address this issue once the related partitioning bugs + (BUG#16002, BUG#15447, BUG#13436) are fixed. + + The NOT_NULL enums are used in TO_DAYS, since TO_DAYS('2001-00-00') returns + NULL which puts those rows into the NULL partition, but + '2000-12-31' < '2001-00-00' < '2001-01-01'. So special handling is needed + for this (see Bug#20577). +*/ + +typedef enum monotonicity_info +{ + NON_MONOTONIC, /* none of the below holds */ + MONOTONIC_INCREASING, /* F() is unary and (x < y) => (F(x) <= F(y)) */ + MONOTONIC_INCREASING_NOT_NULL, /* But only for valid/real x and y */ + MONOTONIC_STRICT_INCREASING,/* F() is unary and (x < y) => (F(x) < F(y)) */ + MONOTONIC_STRICT_INCREASING_NOT_NULL /* But only for valid/real x and y */ +} enum_monotonicity_info; + +/*************************************************************************/ + +class sp_rcontext; + +/** + A helper class to collect different behavior of various kinds of SP variables: + - local SP variables and SP parameters + - PACKAGE BODY routine variables + - (there will be more kinds in the future) +*/ + +class Sp_rcontext_handler +{ +public: + virtual ~Sp_rcontext_handler() {} + /** + A prefix used for SP variable names in queries: + - EXPLAIN EXTENDED + - SHOW PROCEDURE CODE + Local variables and SP parameters have empty prefixes. + Package body variables are marked with a special prefix. + This improves readability of the output of these queries, + especially when a local variable or a parameter has the same + name with a package body variable. + */ + virtual const LEX_CSTRING *get_name_prefix() const= 0; + /** + At execution time THD->spcont points to the run-time context (sp_rcontext) + of the currently executed routine. + Local variables store their data in the sp_rcontext pointed by thd->spcont. + Package body variables store data in separate sp_rcontext that belongs + to the package. + This method provides access to the proper sp_rcontext structure, + depending on the SP variable kind. + */ + virtual sp_rcontext *get_rcontext(sp_rcontext *ctx) const= 0; +}; + + +class Sp_rcontext_handler_local: public Sp_rcontext_handler +{ +public: + const LEX_CSTRING *get_name_prefix() const; + sp_rcontext *get_rcontext(sp_rcontext *ctx) const; +}; + + +class Sp_rcontext_handler_package_body: public Sp_rcontext_handler +{ +public: + const LEX_CSTRING *get_name_prefix() const; + sp_rcontext *get_rcontext(sp_rcontext *ctx) const; +}; + + +extern MYSQL_PLUGIN_IMPORT + Sp_rcontext_handler_local sp_rcontext_handler_local; + + +extern MYSQL_PLUGIN_IMPORT + Sp_rcontext_handler_package_body sp_rcontext_handler_package_body; + + + +class Item_equal; + +struct st_join_table* const NO_PARTICULAR_TAB= (struct st_join_table*)0x1; + +typedef struct replace_equal_field_arg +{ + Item_equal *item_equal; + struct st_join_table *context_tab; +} REPLACE_EQUAL_FIELD_ARG; + +class Settable_routine_parameter +{ +public: + /* + Set required privileges for accessing the parameter. + + SYNOPSIS + set_required_privilege() + rw if 'rw' is true then we are going to read and set the + parameter, so SELECT and UPDATE privileges might be + required, otherwise we only reading it and SELECT + privilege might be required. + */ + Settable_routine_parameter() {} + virtual ~Settable_routine_parameter() {} + virtual void set_required_privilege(bool rw) {}; + + /* + Set parameter value. + + SYNOPSIS + set_value() + thd thread handle + ctx context to which parameter belongs (if it is local + variable). + it item which represents new value + + RETURN + FALSE if parameter value has been set, + TRUE if error has occurred. + */ + virtual bool set_value(THD *thd, sp_rcontext *ctx, Item **it)= 0; + + virtual void set_out_param_info(Send_field *info) {} + + virtual const Send_field *get_out_param_info() const + { return NULL; } + + virtual Item_param *get_item_param() { return 0; } +}; + + +/* + A helper class to calculate offset and length of a query fragment + - outside of SP + - inside an SP + - inside a compound block +*/ +class Query_fragment +{ + uint m_pos; + uint m_length; + void set(size_t pos, size_t length) + { + DBUG_ASSERT(pos < UINT_MAX32); + DBUG_ASSERT(length < UINT_MAX32); + m_pos= (uint) pos; + m_length= (uint) length; + } +public: + Query_fragment(THD *thd, sp_head *sphead, const char *start, const char *end); + uint pos() const { return m_pos; } + uint length() const { return m_length; } +}; + + +/** + This is used for items in the query that needs to be rewritten + before binlogging + + At the moment this applies to Item_param and Item_splocal +*/ +class Rewritable_query_parameter +{ + public: + /* + Offset inside the query text. + Value of 0 means that this object doesn't have to be replaced + (for example SP variables in control statements) + */ + my_ptrdiff_t pos_in_query; + + /* + Byte length of parameter name in the statement. This is not + Item::name.length because name.length contains byte length of UTF8-encoded + name, but the query string is in the client charset. + */ + uint len_in_query; + + bool limit_clause_param; + + Rewritable_query_parameter(uint pos_in_q= 0, uint len_in_q= 0) + : pos_in_query(pos_in_q), len_in_query(len_in_q), + limit_clause_param(false) + { } + + virtual ~Rewritable_query_parameter() { } + + virtual bool append_for_log(THD *thd, String *str) = 0; +}; + +class Copy_query_with_rewrite +{ + THD *thd; + const char *src; + size_t src_len, from; + String *dst; + + bool copy_up_to(size_t bytes) + { + DBUG_ASSERT(bytes >= from); + return dst->append(src + from, uint32(bytes - from)); + } + +public: + + Copy_query_with_rewrite(THD *t, const char *s, size_t l, String *d) + :thd(t), src(s), src_len(l), from(0), dst(d) { } + + bool append(Rewritable_query_parameter *p) + { + if (copy_up_to(p->pos_in_query) || p->append_for_log(thd, dst)) + return true; + from= p->pos_in_query + p->len_in_query; + return false; + } + + bool finalize() + { return copy_up_to(src_len); } +}; + +struct st_dyncall_create_def +{ + Item *key, *value; + CHARSET_INFO *cs; + uint len, frac; + DYNAMIC_COLUMN_TYPE type; +}; + +typedef struct st_dyncall_create_def DYNCALL_CREATE_DEF; + + +typedef bool (Item::*Item_processor) (void *arg); +/* + Analyzer function + SYNOPSIS + argp in/out IN: Analysis parameter + OUT: Parameter to be passed to the transformer + + RETURN + TRUE Invoke the transformer + FALSE Don't do it + +*/ +typedef bool (Item::*Item_analyzer) (uchar **argp); +typedef Item* (Item::*Item_transformer) (THD *thd, uchar *arg); +typedef void (*Cond_traverser) (const Item *item, void *arg); +typedef bool (Item::*Pushdown_checker) (uchar *arg); + +struct st_cond_statistic; + +struct find_selective_predicates_list_processor_data +{ + TABLE *table; + List<st_cond_statistic> list; +}; + +class MY_LOCALE; + +class Item_equal; +class COND_EQUAL; + +class st_select_lex_unit; + +class Item_func_not; +class Item_splocal; + +/* Item::common_flags */ +/* Indicates that name of this Item autogenerated or set by user */ +#define IS_AUTO_GENERATED_NAME 1 +/* Indicates that this item is in CYCLE clause of WITH */ +#define IS_IN_WITH_CYCLE 2 + + +/** + String_copier that sends Item specific warnings. +*/ +class String_copier_for_item: public String_copier +{ + THD *m_thd; +public: + bool copy_with_warn(CHARSET_INFO *dstcs, String *dst, + CHARSET_INFO *srccs, const char *src, + uint32 src_length, uint32 nchars); + String_copier_for_item(THD *thd): m_thd(thd) { } +}; + + +/** + A helper class describing what kind of Item created a temporary field. + - If m_field is set, then the temporary field was created from Field + (e.g. when the Item was Item_field, or Item_ref pointing to Item_field) + - If m_default_field is set, then there is a usable DEFAULT value. + (e.g. when the Item is Item_field) + - If m_item_result_field is set, then the temporary field was created + from certain sub-types of Item_result_field (e.g. Item_func) + See create_tmp_field() in sql_select.cc for details. +*/ + +class Tmp_field_src +{ + Field *m_field; + Field *m_default_field; + Item_result_field *m_item_result_field; +public: + Tmp_field_src() + :m_field(0), + m_default_field(0), + m_item_result_field(0) + { } + Field *field() const { return m_field; } + Field *default_field() const { return m_default_field; } + Item_result_field *item_result_field() const { return m_item_result_field; } + void set_field(Field *field) { m_field= field; } + void set_default_field(Field *field) { m_default_field= field; } + void set_item_result_field(Item_result_field *item) + { m_item_result_field= item; } +}; + + +/** + Parameters for create_tmp_field_ex(). + See create_tmp_field() in sql_select.cc for details. +*/ + +class Tmp_field_param +{ + bool m_group; + bool m_modify_item; + bool m_table_cant_handle_bit_fields; + bool m_make_copy_field; +public: + Tmp_field_param(bool group, + bool modify_item, + bool table_cant_handle_bit_fields, + bool make_copy_field) + :m_group(group), + m_modify_item(modify_item), + m_table_cant_handle_bit_fields(table_cant_handle_bit_fields), + m_make_copy_field(make_copy_field) + { } + bool group() const { return m_group; } + bool modify_item() const { return m_modify_item; } + bool table_cant_handle_bit_fields() const + { return m_table_cant_handle_bit_fields; } + bool make_copy_field() const { return m_make_copy_field; } + void set_modify_item(bool to) { m_modify_item= to; } +}; + + +class Item_const +{ +public: + virtual ~Item_const() {} + virtual const Type_all_attributes *get_type_all_attributes_from_const() const= 0; + virtual bool const_is_null() const { return false; } + virtual const longlong *const_ptr_longlong() const { return NULL; } + virtual const double *const_ptr_double() const { return NULL; } + virtual const my_decimal *const_ptr_my_decimal() const { return NULL; } + virtual const MYSQL_TIME *const_ptr_mysql_time() const { return NULL; } + virtual const String *const_ptr_string() const { return NULL; } +}; + + +/****************************************************************************/ + +#define STOP_PTR ((void *) 1) + +class Item: public Value_source, + public Type_all_attributes +{ + /** + The index in the JOIN::join_tab array of the JOIN_TAB this Item is attached + to. Items are attached (or 'pushed') to JOIN_TABs during optimization by the + make_cond_for_table procedure. During query execution, this item is + evaluated when the join loop reaches the corresponding JOIN_TAB. + + If the value of join_tab_idx >= MAX_TABLES, this means that there is no + corresponding JOIN_TAB. + */ + uint join_tab_idx; + + static void *operator new(size_t size); + +public: + static void *operator new(size_t size, MEM_ROOT *mem_root) throw () + { return alloc_root(mem_root, size); } + static void operator delete(void *ptr,size_t size) { TRASH_FREE(ptr, size); } + static void operator delete(void *ptr, MEM_ROOT *mem_root) {} + + enum Type {FIELD_ITEM= 0, FUNC_ITEM, SUM_FUNC_ITEM, + WINDOW_FUNC_ITEM, + /* + NOT NULL literal-alike constants, which do not change their + value during an SQL statement execution, but can optionally + change their value between statements: + - Item_literal - real NOT NULL constants + - Item_param - can change between statements + - Item_splocal - can change between statements + - Item_user_var_as_out_param - hack + Note, Item_user_var_as_out_param actually abuses the type code. + It should be moved out of the Item tree eventually. + */ + CONST_ITEM, + NULL_ITEM, // Item_null or Item_param bound to NULL + COPY_STR_ITEM, FIELD_AVG_ITEM, DEFAULT_VALUE_ITEM, + CONTEXTUALLY_TYPED_VALUE_ITEM, + PROC_ITEM,COND_ITEM, REF_ITEM, FIELD_STD_ITEM, + FIELD_VARIANCE_ITEM, INSERT_VALUE_ITEM, + SUBSELECT_ITEM, ROW_ITEM, CACHE_ITEM, TYPE_HOLDER, + PARAM_ITEM, TRIGGER_FIELD_ITEM, + EXPR_CACHE_ITEM}; + + enum cond_result { COND_UNDEF,COND_OK,COND_TRUE,COND_FALSE }; + + enum traverse_order { POSTFIX, PREFIX }; + + /* Cache of the result of is_expensive(). */ + int8 is_expensive_cache; + + /* Reuse size, only used by SP local variable assignment, otherwise 0 */ + uint rsize; + +protected: + /* + str_values's main purpose is to be used to cache the value in + save_in_field + */ + String str_value; + + SEL_TREE *get_mm_tree_for_const(RANGE_OPT_PARAM *param); + + /** + Create a field based on the exact data type handler. + */ + Field *create_table_field_from_handler(MEM_ROOT *root, TABLE *table) + { + const Type_handler *h= type_handler(); + return h->make_and_init_table_field(root, &name, + Record_addr(maybe_null), + *this, table); + } + /** + Create a field based on field_type of argument. + This is used to create a field for + - IFNULL(x,something) + - time functions + - prepared statement placeholders + - SP variables with data type references: DECLARE a TYPE OF t1.a; + @retval NULL error + @retval !NULL on success + */ + Field *tmp_table_field_from_field_type(MEM_ROOT *root, TABLE *table) + { + DBUG_ASSERT(is_fixed()); + const Type_handler *h= type_handler()->type_handler_for_tmp_table(this); + return h->make_and_init_table_field(root, &name, + Record_addr(maybe_null), + *this, table); + } + /** + Create a temporary field for a simple Item, which does not + need any special action after the field creation: + - is not an Item_field descendant (and not a reference to Item_field) + - is not an Item_result_field descendant + - does not need to copy any DEFAULT value to the result Field + - does not need to set Field::is_created_from_null_item for the result + See create_tmp_field_ex() for details on parameters and return values. + */ + Field *create_tmp_field_ex_simple(MEM_ROOT *root, + TABLE *table, + Tmp_field_src *src, + const Tmp_field_param *param) + { + DBUG_ASSERT(!param->make_copy_field()); + DBUG_ASSERT(!is_result_field()); + DBUG_ASSERT(type() != NULL_ITEM); + return tmp_table_field_from_field_type(root, table); + } + Field *create_tmp_field_int(MEM_ROOT *root, TABLE *table, + uint convert_int_length); + Field *tmp_table_field_from_field_type_maybe_null(MEM_ROOT *root, + TABLE *table, + Tmp_field_src *src, + const Tmp_field_param *param, + bool is_explicit_null); + + void raise_error_not_evaluable(); + void push_note_converted_to_negative_complement(THD *thd); + void push_note_converted_to_positive_complement(THD *thd); + + /* Helper methods, to get an Item value from another Item */ + double val_real_from_item(Item *item) + { + DBUG_ASSERT(is_fixed()); + double value= item->val_real(); + null_value= item->null_value; + return value; + } + longlong val_int_from_item(Item *item) + { + DBUG_ASSERT(is_fixed()); + longlong value= item->val_int(); + null_value= item->null_value; + return value; + } + String *val_str_from_item(Item *item, String *str) + { + DBUG_ASSERT(is_fixed()); + String *res= item->val_str(str); + if (res) + res->set_charset(collation.collation); + if ((null_value= item->null_value)) + res= NULL; + return res; + } + bool val_native_from_item(THD *thd, Item *item, Native *to) + { + DBUG_ASSERT(is_fixed()); + null_value= item->val_native(thd, to); + DBUG_ASSERT(null_value == item->null_value); + return null_value; + } + bool val_native_from_field(Field *field, Native *to) + { + if ((null_value= field->is_null())) + return true; + return (null_value= field->val_native(to)); + } + bool val_native_with_conversion_from_item(THD *thd, Item *item, Native *to, + const Type_handler *handler) + { + DBUG_ASSERT(is_fixed()); + return null_value= item->val_native_with_conversion(thd, to, handler); + } + my_decimal *val_decimal_from_item(Item *item, my_decimal *decimal_value) + { + DBUG_ASSERT(is_fixed()); + my_decimal *value= item->val_decimal(decimal_value); + if ((null_value= item->null_value)) + value= NULL; + return value; + } + bool get_date_from_item(THD *thd, Item *item, + MYSQL_TIME *ltime, date_mode_t fuzzydate) + { + bool rc= item->get_date(thd, ltime, fuzzydate); + null_value= MY_TEST(rc || item->null_value); + return rc; + } +public: + + /* + Cache val_str() into the own buffer, e.g. to evaluate constant + expressions with subqueries in the ORDER/GROUP clauses. + */ + String *val_str() { return val_str(&str_value); } + virtual Item_func *get_item_func() { return NULL; } + + const MY_LOCALE *locale_from_val_str(); + + LEX_CSTRING name; /* Name of item */ + /* Original item name (if it was renamed)*/ + const char *orig_name; + /** + Intrusive list pointer for free list. If not null, points to the next + Item on some Query_arena's free list. For instance, stored procedures + have their own Query_arena's. + + @see Query_arena::free_list + */ + Item *next; + int marker; + bool maybe_null; /* If item may be null */ + bool in_rollup; /* If used in GROUP BY list + of a query with ROLLUP */ + bool null_value; /* if item is null */ + bool with_param; /* True if contains an SP parameter */ + bool with_window_func; /* True if item contains a window func */ + /** + True if any item except Item_sum contains a field. Set during parsing. + */ + bool with_field; + uint8 common_flags; + bool is_autogenerated_name() + { return (common_flags & IS_AUTO_GENERATED_NAME); } + // alloc & destruct is done as start of select on THD::mem_root + Item(THD *thd); + /* + Constructor used by Item_field, Item_ref & aggregate (sum) functions. + Used for duplicating lists in processing queries with temporary + tables + Also it used for Item_cond_and/Item_cond_or for creating + top AND/OR structure of WHERE clause to protect it of + optimisation changes in prepared statements + */ + Item(THD *thd, Item *item); + virtual ~Item() + { +#ifdef EXTRA_DEBUG + name.str= 0; + name.length= 0; +#endif + } /*lint -e1509 */ + void set_name(THD *thd, const char *str, size_t length, CHARSET_INFO *cs); + void set_name(THD *thd, String *str) + { + set_name(thd, str->ptr(), str->length(), str->charset()); + } + void set_name(THD *thd, const LEX_CSTRING &str, + CHARSET_INFO *cs= system_charset_info) + { + set_name(thd, str.str, str.length, cs); + } + void set_name_no_truncate(THD *thd, const char *str, uint length, + CHARSET_INFO *cs); + void init_make_send_field(Send_field *tmp_field, const Type_handler *h); + void share_name_with(const Item *item) + { + name= item->name; + common_flags= static_cast<uint8> + ((common_flags & ~IS_AUTO_GENERATED_NAME) | + (item->common_flags & IS_AUTO_GENERATED_NAME)); + } + virtual void cleanup(); + virtual void make_send_field(THD *thd, Send_field *field); + + bool fix_fields_if_needed(THD *thd, Item **ref) + { + return is_fixed() ? false : fix_fields(thd, ref); + } + bool fix_fields_if_needed_for_scalar(THD *thd, Item **ref) + { + return fix_fields_if_needed(thd, ref) || check_cols(1); + } + bool fix_fields_if_needed_for_bool(THD *thd, Item **ref) + { + return fix_fields_if_needed_for_scalar(thd, ref); + } + bool fix_fields_if_needed_for_order_by(THD *thd, Item **ref) + { + return fix_fields_if_needed_for_scalar(thd, ref); + } + /* + By default we assume that an Item is fixed by the contstructor. + */ + virtual bool fix_fields(THD *, Item **) + { + /* + This should not normally be called, because usually before + fix_fields() we check is_fixed() to be false. + But historically we allow fix_fields() to be called for Items + who return basic_const_item()==true. + */ + DBUG_ASSERT(is_fixed()); + DBUG_ASSERT(basic_const_item()); + return false; + } + virtual bool is_fixed() const { return true; } + virtual void unfix_fields() + { + DBUG_ASSERT(0); + } + + /* + Fix after some tables has been pulled out. Basically re-calculate all + attributes that are dependent on the tables. + */ + virtual void fix_after_pullout(st_select_lex *new_parent, Item **ref, + bool merge) + {}; + + /* + This method should be used in case where we are sure that we do not need + complete fix_fields() procedure. + Usually this method is used by the optimizer when it has to create a new + item out of other already fixed items. For example, if the optimizer has + to create a new Item_func for an inferred equality whose left and right + parts are already fixed items. In some cases the optimizer cannot use + directly fixed items as the arguments of the created functional item, + but rather uses intermediate type conversion items. Then the method is + supposed to be applied recursively. + */ + virtual void quick_fix_field() + { + DBUG_ASSERT(0); + } + + bool save_in_value(THD *thd, struct st_value *value) + { + return type_handler()->Item_save_in_value(thd, this, value); + } + + /* Function returns 1 on overflow and -1 on fatal errors */ + int save_in_field_no_warnings(Field *field, bool no_conversions); + virtual int save_in_field(Field *field, bool no_conversions); + virtual bool save_in_param(THD *thd, Item_param *param); + virtual void save_org_in_field(Field *field, + fast_field_copier data + __attribute__ ((__unused__))) + { (void) save_in_field(field, 1); } + virtual fast_field_copier setup_fast_field_copier(Field *field) + { return NULL; } + virtual int save_safe_in_field(Field *field) + { return save_in_field(field, 1); } + virtual bool send(Protocol *protocol, st_value *buffer) + { + return type_handler()->Item_send(this, protocol, buffer); + } + virtual bool eq(const Item *, bool binary_cmp) const; + enum_field_types field_type() const + { + return type_handler()->field_type(); + } + virtual const Type_handler *type_handler() const= 0; + /** + Detects if an Item has a fixed data type which is known + even before fix_fields(). + Currently it's important only to find Items with a fixed boolean + data type. More item types can be marked in the future as having + a fixed data type (e.g. all literals, all fixed type functions, etc). + + @retval NULL if the Item type is not known before fix_fields() + @retval the pointer to the data type handler, if the data type + is known before fix_fields(). + */ + virtual const Type_handler *fixed_type_handler() const + { + return NULL; + } + const Type_handler *type_handler_for_comparison() const + { + return type_handler()->type_handler_for_comparison(); + } + virtual const Type_handler *real_type_handler() const + { + return type_handler(); + } + const Type_handler *cast_to_int_type_handler() const + { + return real_type_handler()->cast_to_int_type_handler(); + } + /* result_type() of an item specifies how the value should be returned */ + Item_result result_type() const + { + return type_handler()->result_type(); + } + /* ... while cmp_type() specifies how it should be compared */ + Item_result cmp_type() const + { + return type_handler()->cmp_type(); + } + const Type_handler *string_type_handler() const + { + return Type_handler::string_type_handler(max_length); + } + /* + Calculate the maximum length of an expression. + This method is used in data type aggregation for UNION, e.g.: + SELECT 'b' UNION SELECT COALESCE(double_10_3_field) FROM t1; + + The result is usually equal to max_length, except for some numeric types. + In case of the INT, FLOAT, DOUBLE data types Item::max_length and + Item::decimals are ignored, so the returned value depends only on the + data type itself. E.g. for an expression of the DOUBLE(10,3) data type, + the result is always 53 (length 10 and precision 3 do not matter). + + max_length is ignored for these numeric data types because the length limit + means only "expected maximum length", it is not a hard limit, so it does + not impose any data truncation. E.g. a column of the type INT(4) can + normally store big values up to 2147483647 without truncation. When we're + aggregating such column for UNION it's important to create a long enough + result column, not to lose any data. + + For detailed behaviour of various data types see implementations of + the corresponding Type_handler_xxx::max_display_length(). + + Note, Item_field::max_display_length() overrides this to get + max_display_length() from the underlying field. + */ + virtual uint32 max_display_length() const + { + return type_handler()->max_display_length(this); + } + const TYPELIB *get_typelib() const { return NULL; } + void set_maybe_null(bool maybe_null_arg) { maybe_null= maybe_null_arg; } + void set_typelib(const TYPELIB *typelib) + { + // Non-field Items (e.g. hybrid functions) never have ENUM/SET types yet. + DBUG_ASSERT(0); + } + Item_cache* get_cache(THD *thd) const + { + return type_handler()->Item_get_cache(thd, this); + } + virtual enum Type type() const =0; + bool is_of_type(Type t, Item_result cmp) const + { + return type() == t && cmp_type() == cmp; + } + /* + real_type() is the type of base item. This is same as type() for + most items, except Item_ref() and Item_cache_wrapper() where it + shows the type for the underlying item. + */ + virtual enum Type real_type() const { return type(); } + + /* + Return information about function monotonicity. See comment for + enum_monotonicity_info for details. This function can only be called + after fix_fields() call. + */ + virtual enum_monotonicity_info get_monotonicity_info() const + { return NON_MONOTONIC; } + + /* + Convert "func_arg $CMP$ const" half-interval into "FUNC(func_arg) $CMP2$ const2" + + SYNOPSIS + val_int_endpoint() + left_endp FALSE <=> The interval is "x < const" or "x <= const" + TRUE <=> The interval is "x > const" or "x >= const" + + incl_endp IN FALSE <=> the comparison is '<' or '>' + TRUE <=> the comparison is '<=' or '>=' + OUT The same but for the "F(x) $CMP$ F(const)" comparison + + DESCRIPTION + This function is defined only for unary monotonic functions. The caller + supplies the source half-interval + + x $CMP$ const + + The value of const is supplied implicitly as the value this item's + argument, the form of $CMP$ comparison is specified through the + function's arguments. The calle returns the result interval + + F(x) $CMP2$ F(const) + + passing back F(const) as the return value, and the form of $CMP2$ + through the out parameter. NULL values are assumed to be comparable and + be less than any non-NULL values. + + RETURN + The output range bound, which equal to the value of val_int() + - If the value of the function is NULL then the bound is the + smallest possible value of LONGLONG_MIN + */ + virtual longlong val_int_endpoint(bool left_endp, bool *incl_endp) + { DBUG_ASSERT(0); return 0; } + + + /* valXXX methods must return NULL or 0 or 0.0 if null_value is set. */ + /* + Return double precision floating point representation of item. + + SYNOPSIS + val_real() + + RETURN + In case of NULL value return 0.0 and set null_value flag to TRUE. + If value is not null null_value flag will be reset to FALSE. + */ + virtual double val_real()=0; + Double_null to_double_null() + { + // val_real() must be caleed on a separate line. See to_longlong_null() + double nr= val_real(); + return Double_null(nr, null_value); + } + /* + Return integer representation of item. + + SYNOPSIS + val_int() + + RETURN + In case of NULL value return 0 and set null_value flag to TRUE. + If value is not null null_value flag will be reset to FALSE. + */ + virtual longlong val_int()=0; + Longlong_hybrid to_longlong_hybrid() + { + return Longlong_hybrid(val_int(), unsigned_flag); + } + Longlong_null to_longlong_null() + { + longlong nr= val_int(); + /* + C++ does not guarantee the order of parameter evaluation, + so to make sure "null_value" is passed to the constructor + after the val_int() call, val_int() is caled on a separate line. + */ + return Longlong_null(nr, null_value); + } + Longlong_hybrid_null to_longlong_hybrid_null() + { + return Longlong_hybrid_null(to_longlong_null(), unsigned_flag); + } + /** + Get a value for CAST(x AS SIGNED). + Too large positive unsigned integer values are converted + to negative complements. + Values of non-integer data types are adjusted to the SIGNED range. + */ + virtual longlong val_int_signed_typecast() + { + return cast_to_int_type_handler()->Item_val_int_signed_typecast(this); + } + longlong val_int_signed_typecast_from_str(); + /** + Get a value for CAST(x AS UNSIGNED). + Negative signed integer values are converted + to positive complements. + Values of non-integer data types are adjusted to the UNSIGNED range. + */ + virtual longlong val_int_unsigned_typecast() + { + return cast_to_int_type_handler()->Item_val_int_unsigned_typecast(this); + } + longlong val_int_unsigned_typecast_from_int(); + longlong val_int_unsigned_typecast_from_str(); + longlong val_int_unsigned_typecast_from_real(); + + /** + Get a value for CAST(x AS UNSIGNED). + Huge positive unsigned values are converted to negative complements. + */ + longlong val_int_signed_typecast_from_int(); + longlong val_int_signed_typecast_from_real(); + + /* + This is just a shortcut to avoid the cast. You should still use + unsigned_flag to check the sign of the item. + */ + inline ulonglong val_uint() { return (ulonglong) val_int(); } + + /* + Return string representation of this item object. + + SYNOPSIS + val_str() + str an allocated buffer this or any nested Item object can use to + store return value of this method. + + NOTE + The caller can modify the returned String, if it's not marked + "const" (with the String::mark_as_const() method). That means that + if the item returns its own internal buffer (e.g. tmp_value), it + *must* be marked "const" [1]. So normally it's preferable to + return the result value in the String, that was passed as an + argument. But, for example, SUBSTR() returns a String that simply + points into the buffer of SUBSTR()'s args[0]->val_str(). Such a + String is always "const", so it's ok to use tmp_value for that and + avoid reallocating/copying of the argument String. + + [1] consider SELECT CONCAT(f, ":", f) FROM (SELECT func() AS f); + here the return value of f() is used twice in the top-level + select, and if they share the same tmp_value buffer, modifying the + first one will implicitly modify the second too. + + RETURN + In case of NULL value return 0 (NULL pointer) and set null_value flag + to TRUE. + If value is not null null_value flag will be reset to FALSE. + */ + virtual String *val_str(String *str)=0; + + + bool val_native_with_conversion(THD *thd, Native *to, const Type_handler *th) + { + return th->Item_val_native_with_conversion(thd, this, to); + } + bool val_native_with_conversion_result(THD *thd, Native *to, + const Type_handler *th) + { + return th->Item_val_native_with_conversion_result(thd, this, to); + } + + virtual bool val_native(THD *thd, Native *to) + { + /* + The default implementation for the Items that do not need native format: + - Item_basic_value (default implementation) + - Item_copy + - Item_exists_subselect + - Item_sum_field + - Item_sum_or_func (default implementation) + - Item_proc + - Item_type_holder (as val_xxx() are never called for it); + + These hybrid Item types override val_native(): + - Item_field + - Item_param + - Item_sp_variable + - Item_ref + - Item_cache_wrapper + - Item_direct_ref + - Item_direct_view_ref + - Item_ref_null_helper + - Item_name_const + - Item_time_literal + - Item_sum_or_func + Note, these hybrid type Item_sum_or_func descendants + override the default implementation: + * Item_sum_hybrid + * Item_func_hybrid_field_type + * Item_func_min_max + * Item_func_sp + * Item_func_last_value + * Item_func_rollup_const + */ + DBUG_ASSERT(0); + return null_value= true; + } + virtual bool val_native_result(THD *thd, Native *to) + { + return val_native(thd, to); + } + + /* + Returns string representation of this item in ASCII format. + + SYNOPSIS + val_str_ascii() + str - similar to val_str(); + + NOTE + This method is introduced for performance optimization purposes. + + 1. val_str() result of some Items in string context + depends on @@character_set_results. + @@character_set_results can be set to a "real multibyte" character + set like UCS2, UTF16, UTF32. (We'll use only UTF32 in the examples + below for convenience.) + + So the default string result of such functions + in these circumstances is real multi-byte character set, like UTF32. + + For example, all numbers in string context + return result in @@character_set_results: + + SELECT CONCAT(20010101); -> UTF32 + + We do sprintf() first (to get ASCII representation) + and then convert to UTF32; + + So these kind "data sources" can use ASCII representation + internally, but return multi-byte data only because + @@character_set_results wants so. + Therefore, conversion from ASCII to UTF32 is applied internally. + + + 2. Some other functions need in fact ASCII input. + + For example, + inet_aton(), GeometryFromText(), Convert_TZ(), GET_FORMAT(). + + Similar, fields of certain type, like DATE, TIME, + when you insert string data into them, expect in fact ASCII input. + If they get non-ASCII input, for example UTF32, they + convert input from UTF32 to ASCII, and then use ASCII + representation to do further processing. + + + 3. Now imagine we pass result of a data source of the first type + to a data destination of the second type. + + What happens: + a. data source converts data from ASCII to UTF32, because + @@character_set_results wants so and passes the result to + data destination. + b. data destination gets UTF32 string. + c. data destination converts UTF32 string to ASCII, + because it needs ASCII representation to be able to handle data + correctly. + + As a result we get two steps of unnecessary conversion: + From ASCII to UTF32, then from UTF32 to ASCII. + + A better way to handle these situations is to pass ASCII + representation directly from the source to the destination. + + This is why val_str_ascii() introduced. + + RETURN + Similar to val_str() + */ + virtual String *val_str_ascii(String *str); + + /* + Returns the result of val_str_ascii(), translating NULLs back + to empty strings (if MODE_EMPTY_STRING_IS_NULL is set). + */ + String *val_str_ascii_revert_empty_string_is_null(THD *thd, String *str); + + /* + Returns the val_str() value converted to the given character set. + */ + String *val_str(String *str, String *converter, CHARSET_INFO *to); + + virtual String *val_json(String *str) { return val_str(str); } + /* + Return decimal representation of item with fixed point. + + SYNOPSIS + val_decimal() + decimal_buffer buffer which can be used by Item for returning value + (but can be not) + + NOTE + Returned value should not be changed if it is not the same which was + passed via argument. + + RETURN + Return pointer on my_decimal (it can be other then passed via argument) + if value is not NULL (null_value flag will be reset to FALSE). + In case of NULL value it return 0 pointer and set null_value flag + to TRUE. + */ + virtual my_decimal *val_decimal(my_decimal *decimal_buffer)= 0; + /* + Return boolean value of item. + + RETURN + FALSE value is false or NULL + TRUE value is true (not equal to 0) + */ + virtual bool val_bool() + { + return type_handler()->Item_val_bool(this); + } + + bool eval_const_cond() + { + DBUG_ASSERT(const_item()); + DBUG_ASSERT(!is_expensive()); + return val_bool(); + } + + /* + save_val() is method of val_* family which stores value in the given + field. + */ + virtual void save_val(Field *to) { save_org_in_field(to, NULL); } + /* + save_result() is method of val*result() family which stores value in + the given field. + */ + virtual void save_result(Field *to) { save_val(to); } + /* Helper functions, see item_sum.cc */ + String *val_string_from_real(String *str); + String *val_string_from_int(String *str); + my_decimal *val_decimal_from_real(my_decimal *decimal_value); + my_decimal *val_decimal_from_int(my_decimal *decimal_value); + my_decimal *val_decimal_from_string(my_decimal *decimal_value); + longlong val_int_from_real() + { + DBUG_ASSERT(is_fixed()); + return Converter_double_to_longlong_with_warn(val_real(), false).result(); + } + longlong val_int_from_str(int *error); + + /* + Returns true if this item can be calculated during + value_depends_on_sql_mode() + */ + bool value_depends_on_sql_mode_const_item() + { + /* + Currently we use value_depends_on_sql_mode() only for virtual + column expressions. They should not contain any expensive items. + If we ever get a crash on the assert below, it means + check_vcol_func_processor() is badly implemented for this item. + */ + DBUG_ASSERT(!is_expensive()); + /* + It should return const_item() actually. + But for some reasons Item_field::const_item() returns true + at value_depends_on_sql_mode() call time. + This should be checked and fixed. + */ + return basic_const_item(); + } + virtual Sql_mode_dependency value_depends_on_sql_mode() const + { + return Sql_mode_dependency(); + } + + int save_time_in_field(Field *field, bool no_conversions); + int save_date_in_field(Field *field, bool no_conversions); + int save_str_in_field(Field *field, bool no_conversions); + int save_real_in_field(Field *field, bool no_conversions); + int save_int_in_field(Field *field, bool no_conversions); + int save_decimal_in_field(Field *field, bool no_conversions); + + int save_str_value_in_field(Field *field, String *result); + + virtual Field *get_tmp_table_field() { return 0; } + virtual Field *create_field_for_create_select(MEM_ROOT *root, TABLE *table); + virtual const char *full_name() const { return name.str ? name.str : "???"; } + const char *field_name_or_null() + { return real_item()->type() == Item::FIELD_ITEM ? name.str : NULL; } + const TABLE_SHARE *field_table_or_null(); + + /* + *result* family of methods is analog of *val* family (see above) but + return value of result_field of item if it is present. If Item have not + result field, it return val(). This methods set null_value flag in same + way as *val* methods do it. + */ + virtual double val_result() { return val_real(); } + virtual longlong val_int_result() { return val_int(); } + virtual String *str_result(String* tmp) { return val_str(tmp); } + virtual my_decimal *val_decimal_result(my_decimal *val) + { return val_decimal(val); } + virtual bool val_bool_result() { return val_bool(); } + virtual bool is_null_result() { return is_null(); } + /* + Returns 1 if result type and collation for val_str() can change between + calls + */ + virtual bool dynamic_result() { return 0; } + /* + Bitmap of tables used by item + (note: if you need to check dependencies on individual columns, check out + class Field_enumerator) + */ + virtual table_map used_tables() const { return (table_map) 0L; } + virtual table_map all_used_tables() const { return used_tables(); } + /* + Return table map of tables that can't be NULL tables (tables that are + used in a context where if they would contain a NULL row generated + by a LEFT or RIGHT join, the item would not be true). + This expression is used on WHERE item to determinate if a LEFT JOIN can be + converted to a normal join. + Generally this function should return used_tables() if the function + would return null if any of the arguments are null + As this is only used in the beginning of optimization, the value don't + have to be updated in update_used_tables() + */ + virtual table_map not_null_tables() const { return used_tables(); } + /* + Returns true if this is a simple constant item like an integer, not + a constant expression. Used in the optimizer to propagate basic constants. + */ + virtual bool basic_const_item() const { return 0; } + /** + Determines if the expression is allowed as + a virtual column assignment source: + INSERT INTO t1 (vcol) VALUES (10) -> error + INSERT INTO t1 (vcol) VALUES (NULL) -> ok + */ + virtual bool vcol_assignment_allowed_value() const { return false; } + /** + Test if "this" is an ORDER position (rather than an expression). + Notes: + - can be called before fix_fields(). + - local SP variables (even of integer types) are always expressions, not + positions. (And they can't be used before fix_fields is called for them). + */ + virtual bool is_order_clause_position() const { return false; } + /* + Determines if the Item is an evaluable expression, that is + it can return a value, so we can call methods val_xxx(), get_date(), etc. + Most items are evaluable expressions. + Examples of non-evaluable expressions: + - Item_contextually_typed_value_specification (handling DEFAULT and IGNORE) + - Item_type_param bound to DEFAULT and IGNORE + We cannot call the mentioned methods for these Items, + their method implementations typically have DBUG_ASSERT(0). + */ + virtual bool is_evaluable_expression() const { return true; } + bool check_is_evaluable_expression_or_error() + { + if (is_evaluable_expression()) + return false; // Ok + raise_error_not_evaluable(); + return true; // Error + } + /* cloning of constant items (0 if it is not const) */ + virtual Item *clone_item(THD *thd) { return 0; } + /* deep copy item */ + virtual Item* build_clone(THD *thd) { return get_copy(thd); } + virtual cond_result eq_cmp_result() const { return COND_OK; } + inline uint float_length(uint decimals_par) const + { return decimals < FLOATING_POINT_DECIMALS ? (DBL_DIG+2+decimals_par) : DBL_DIG+8;} + /* Returns total number of decimal digits */ + virtual uint decimal_precision() const + { + return type_handler()->Item_decimal_precision(this); + } + /* Returns the number of integer part digits only */ + inline int decimal_int_part() const + { return my_decimal_int_part(decimal_precision(), decimals); } + /* + Returns the number of fractional digits only. + NOT_FIXED_DEC is replaced to the maximum possible number + of fractional digits, taking into account the data type. + */ + uint decimal_scale() const + { + return type_handler()->Item_decimal_scale(this); + } + /* + Returns how many digits a divisor adds into a division result. + This is important when the integer part of the divisor can be 0. + In this example: + SELECT 1 / 0.000001; -> 1000000.0000 + the divisor adds 5 digits into the result precision. + + Currently this method only replaces NOT_FIXED_DEC to + TIME_SECOND_PART_DIGITS for temporal data types. + This method can be made virtual, to create more efficient (smaller) + data types for division results. + For example, in + SELECT 1/1.000001; + the divisor could provide no additional precision into the result, + so could any other items that are know to return a result + with non-zero integer part. + */ + uint divisor_precision_increment() const + { + return type_handler()->Item_divisor_precision_increment(this); + } + /** + TIME or DATETIME precision of the item: 0..6 + */ + uint time_precision(THD *thd) + { + return const_item() ? type_handler()->Item_time_precision(thd, this) : + MY_MIN(decimals, TIME_SECOND_PART_DIGITS); + } + uint datetime_precision(THD *thd) + { + return const_item() ? type_handler()->Item_datetime_precision(thd, this) : + MY_MIN(decimals, TIME_SECOND_PART_DIGITS); + } + virtual longlong val_int_min() const + { + return LONGLONG_MIN; + } + /* + Returns true if this is constant (during query execution, i.e. its value + will not change until next fix_fields) and its value is known. + */ + virtual bool const_item() const { return used_tables() == 0; } + /* + Returns true if this is constant but its value may be not known yet. + (Can be used for parameters of prep. stmts or of stored procedures.) + */ + virtual bool const_during_execution() const + { return (used_tables() & ~PARAM_TABLE_BIT) == 0; } + + /** + This method is used for to: + - to generate a view definition query (SELECT-statement); + - to generate a SQL-query for EXPLAIN EXTENDED; + - to generate a SQL-query to be shown in INFORMATION_SCHEMA; + - debug. + + For more information about view definition query, INFORMATION_SCHEMA + query and why they should be generated from the Item-tree, @see + mysql_register_view(). + */ + virtual enum precedence precedence() const { return DEFAULT_PRECEDENCE; } + enum precedence higher_precedence() const + { return (enum precedence)(precedence() + 1); } + void print_parenthesised(String *str, enum_query_type query_type, + enum precedence parent_prec); + /** + This helper is used to print expressions as a part of a table definition, + in particular for + - generated columns + - check constraints + - default value expressions + - partitioning expressions + */ + void print_for_table_def(String *str) + { + print_parenthesised(str, + (enum_query_type)(QT_ITEM_ORIGINAL_FUNC_NULLIF | + QT_ITEM_IDENT_SKIP_DB_NAMES | + QT_ITEM_IDENT_SKIP_TABLE_NAMES | + QT_NO_DATA_EXPANSION | + QT_TO_SYSTEM_CHARSET), + LOWEST_PRECEDENCE); + } + virtual void print(String *str, enum_query_type query_type); + + class Print: public String + { + public: + Print(Item *item, enum_query_type type) + { + item->print(this, type); + } + }; + + void print_item_w_name(String *str, enum_query_type query_type); + void print_value(String *str); + + virtual void update_used_tables() {} + virtual COND *build_equal_items(THD *thd, COND_EQUAL *inheited, + bool link_item_fields, + COND_EQUAL **cond_equal_ref) + { + update_used_tables(); + DBUG_ASSERT(!cond_equal_ref || !cond_equal_ref[0]); + return this; + } + virtual COND *remove_eq_conds(THD *thd, Item::cond_result *cond_value, + bool top_level); + virtual void add_key_fields(JOIN *join, KEY_FIELD **key_fields, + uint *and_level, + table_map usable_tables, + SARGABLE_PARAM **sargables) + { + return; + } + /* + Make a select tree for all keys in a condition or a condition part + @param param Context + @param cond_ptr[OUT] Store a replacement item here if the condition + can be simplified, e.g.: + WHERE part1 OR part2 OR part3 + with one of the partN evaluating to SEL_TREE::ALWAYS. + */ + virtual SEL_TREE *get_mm_tree(RANGE_OPT_PARAM *param, Item **cond_ptr); + /* + Checks whether the item is: + - a simple equality (field=field_item or field=constant_item), or + - a row equality + and form multiple equality predicates. + */ + virtual bool check_equality(THD *thd, COND_EQUAL *cond, List<Item> *eq_list) + { + return false; + } + virtual void split_sum_func(THD *thd, Ref_ptr_array ref_pointer_array, + List<Item> &fields, uint flags) {} + /* Called for items that really have to be split */ + void split_sum_func2(THD *thd, Ref_ptr_array ref_pointer_array, + List<Item> &fields, + Item **ref, uint flags); + virtual bool get_date(THD *thd, MYSQL_TIME *ltime, date_mode_t fuzzydate)= 0; + bool get_date_from_int(THD *thd, MYSQL_TIME *ltime, date_mode_t fuzzydate); + bool get_date_from_real(THD *thd, MYSQL_TIME *ltime, date_mode_t fuzzydate); + bool get_date_from_string(THD *thd, MYSQL_TIME *ltime, date_mode_t fuzzydate); + bool get_time(THD *thd, MYSQL_TIME *ltime) + { return get_date(thd, ltime, Time::Options(thd)); } + // Get a DATE or DATETIME value in numeric packed format for comparison + virtual longlong val_datetime_packed(THD *thd) + { + return Datetime(thd, this, Datetime::Options_cmp(thd)).to_packed(); + } + // Get a TIME value in numeric packed format for comparison + virtual longlong val_time_packed(THD *thd) + { + return Time(thd, this, Time::Options_cmp(thd)).to_packed(); + } + longlong val_datetime_packed_result(THD *thd); + longlong val_time_packed_result(THD *thd); + + virtual bool get_date_result(THD *thd, MYSQL_TIME *ltime, date_mode_t fuzzydate) + { return get_date(thd, ltime,fuzzydate); } + + /* + The method allows to determine nullness of a complex expression + without fully evaluating it, instead of calling val/result*() then + checking null_value. Used in Item_func_isnull/Item_func_isnotnull + and Item_sum_count. + Any new item which can be NULL must implement this method. + */ + virtual bool is_null() { return 0; } + + /* + Make sure the null_value member has a correct value. + */ + virtual void update_null_value () + { + return type_handler()->Item_update_null_value(this); + } + + /* + Inform the item that there will be no distinction between its result + being FALSE or NULL. + + NOTE + This function will be called for eg. Items that are top-level AND-parts + of the WHERE clause. Items implementing this function (currently + Item_cond_and and subquery-related item) enable special optimizations + when they are "top level". + */ + virtual void top_level_item() {} + /* + Return TRUE if it is item of top WHERE level (AND/OR) and it is + important, return FALSE if it not important (we can not use to simplify + calculations) or not top level + */ + virtual bool is_top_level_item() const + { return FALSE; /* not important */} + /* + return IN/ALL/ANY subquery or NULL + */ + virtual Item_in_subselect* get_IN_subquery() + { return NULL; /* in is not IN/ALL/ANY */ } + /* + set field of temporary table for Item which can be switched on temporary + table during query processing (grouping and so on) + */ + virtual bool is_result_field() { return 0; } + virtual bool is_json_type() { return false; } + virtual bool is_bool_literal() const { return false; } + /* This is to handle printing of default values */ + virtual bool need_parentheses_in_default() { return false; } + virtual void save_in_result_field(bool no_conversions) {} + /* + Data type format implied by the CHECK CONSTRAINT, + to be sent to the client in the result set metadata. + */ + virtual bool set_format_by_check_constraint(Send_field_extended_metadata *) + const + { + return false; + } + /* + set value of aggregate function in case of no rows for grouping were found + */ + virtual void no_rows_in_result() {} + virtual void restore_to_before_no_rows_in_result() {} + virtual Item *copy_or_same(THD *thd) { return this; } + virtual Item *copy_andor_structure(THD *thd) { return this; } + virtual Item *real_item() { return this; } + virtual Item *get_tmp_table_item(THD *thd) { return copy_or_same(thd); } + virtual Item *make_odbc_literal(THD *thd, const LEX_CSTRING *typestr) + { + return this; + } + + static CHARSET_INFO *default_charset(); + + CHARSET_INFO *charset_for_protocol(void) const + { + return type_handler()->charset_for_protocol(this); + }; + + virtual bool walk(Item_processor processor, bool walk_subquery, void *arg) + { + return (this->*processor)(arg); + } + + virtual Item* transform(THD *thd, Item_transformer transformer, uchar *arg); + + /* + This function performs a generic "compilation" of the Item tree. + The process of compilation is assumed to go as follows: + + compile() + { + if (this->*some_analyzer(...)) + { + compile children if any; + this->*some_transformer(...); + } + } + + i.e. analysis is performed top-down while transformation is done + bottom-up. + */ + virtual Item* compile(THD *thd, Item_analyzer analyzer, uchar **arg_p, + Item_transformer transformer, uchar *arg_t) + { + if ((this->*analyzer) (arg_p)) + return ((this->*transformer) (thd, arg_t)); + return 0; + } + + virtual void traverse_cond(Cond_traverser traverser, + void *arg, traverse_order order) + { + (*traverser)(this, arg); + } + + /*========= Item processors, to be used with Item::walk() ========*/ + virtual bool remove_dependence_processor(void *arg) { return 0; } + virtual bool cleanup_processor(void *arg); + virtual bool cleanup_excluding_fields_processor (void *arg) + { return cleanup_processor(arg); } + bool cleanup_excluding_immutables_processor (void *arg); + virtual bool cleanup_excluding_const_fields_processor (void *arg) + { return cleanup_processor(arg); } + virtual bool collect_item_field_processor(void *arg) { return 0; } + virtual bool unknown_splocal_processor(void *arg) { return 0; } + virtual bool collect_outer_ref_processor(void *arg) {return 0; } + virtual bool check_inner_refs_processor(void *arg) { return 0; } + virtual bool find_item_in_field_list_processor(void *arg) { return 0; } + virtual bool find_item_processor(void *arg); + virtual bool change_context_processor(void *arg) { return 0; } + virtual bool reset_query_id_processor(void *arg) { return 0; } + virtual bool is_expensive_processor(void *arg) { return 0; } + + // FIXME reduce the number of "add field to bitmap" processors + virtual bool add_field_to_set_processor(void *arg) { return 0; } + virtual bool register_field_in_read_map(void *arg) { return 0; } + virtual bool register_field_in_write_map(void *arg) { return 0; } + virtual bool register_field_in_bitmap(void *arg) { return 0; } + virtual bool update_table_bitmaps_processor(void *arg) { return 0; } + + virtual bool enumerate_field_refs_processor(void *arg) { return 0; } + virtual bool mark_as_eliminated_processor(void *arg) { return 0; } + virtual bool eliminate_subselect_processor(void *arg) { return 0; } + virtual bool set_fake_select_as_master_processor(void *arg) { return 0; } + virtual bool view_used_tables_processor(void *arg) { return 0; } + virtual bool eval_not_null_tables(void *arg) { return 0; } + virtual bool is_subquery_processor(void *arg) { return 0; } + virtual bool count_sargable_conds(void *arg) { return 0; } + virtual bool limit_index_condition_pushdown_processor(void *arg) { return 0; } + virtual bool exists2in_processor(void *arg) { return 0; } + virtual bool find_selective_predicates_list_processor(void *arg) { return 0; } + bool cleanup_is_expensive_cache_processor(void *arg) + { + is_expensive_cache= (int8)(-1); + return 0; + } + + /** + Check db/table_name if they defined in item and match arg values + + @param arg Pointer to Check_table_name_prm structure + + @retval true Match failed + @retval false Match succeeded + */ + virtual bool check_table_name_processor(void *arg) { return false; } + /* + TRUE if the expression depends only on the table indicated by tab_map + or can be converted to such an exression using equalities. + Not to be used for AND/OR formulas. + */ + virtual bool excl_dep_on_table(table_map tab_map) { return false; } + /* + TRUE if the expression depends only on grouping fields of sel + or can be converted to such an expression using equalities. + It also checks if the expression doesn't contain stored procedures, + subqueries or randomly generated elements. + Not to be used for AND/OR formulas. + */ + virtual bool excl_dep_on_grouping_fields(st_select_lex *sel) + { return false; } + /* + TRUE if the expression depends only on fields from the left part of + IN subquery or can be converted to such an expression using equalities. + Not to be used for AND/OR formulas. + */ + virtual bool excl_dep_on_in_subq_left_part(Item_in_subselect *subq_pred) + { return false; } + + virtual bool switch_to_nullable_fields_processor(void *arg) { return 0; } + virtual bool find_function_processor (void *arg) { return 0; } + /* + Check if a partition function is allowed + SYNOPSIS + check_partition_func_processor() + int_arg Ignored + RETURN VALUE + TRUE Partition function not accepted + FALSE Partition function accepted + + DESCRIPTION + check_partition_func_processor is used to check if a partition function + uses an allowed function. An allowed function will always ensure that + X=Y guarantees that also part_function(X)=part_function(Y) where X is + a set of partition fields and so is Y. The problems comes mainly from + character sets where two equal strings can be quite unequal. E.g. the + german character for double s is equal to 2 s. + + The default is that an item is not allowed + in a partition function. Allowed functions + can never depend on server version, they cannot depend on anything + related to the environment. They can also only depend on a set of + fields in the table itself. They cannot depend on other tables and + cannot contain any queries and cannot contain udf's or similar. + If a new Item class is defined and it inherits from a class that is + allowed in a partition function then it is very important to consider + whether this should be inherited to the new class. If not the function + below should be defined in the new Item class. + + The general behaviour is that most integer functions are allowed. + If the partition function contains any multi-byte collations then + the function check_part_func_fields will report an error on the + partition function independent of what functions are used. So the + only character sets allowed are single character collation and + even for those only a limited set of functions are allowed. The + problem with multi-byte collations is that almost every string + function has the ability to change things such that two strings + that are equal will not be equal after manipulated by a string + function. E.g. two strings one contains a double s, there is a + special german character that is equal to two s. Now assume a + string function removes one character at this place, then in + one the double s will be removed and in the other there will + still be one s remaining and the strings are no longer equal + and thus the partition function will not sort equal strings into + the same partitions. + + So the check if a partition function is valid is two steps. First + check that the field types are valid, next check that the partition + function is valid. The current set of partition functions valid + assumes that there are no multi-byte collations amongst the partition + fields. + */ + virtual bool check_partition_func_processor(void *arg) { return 1;} + virtual bool post_fix_fields_part_expr_processor(void *arg) { return 0; } + virtual bool rename_fields_processor(void *arg) { return 0; } + /* + TRUE if the function is knowingly TRUE or FALSE. + Not to be used for AND/OR formulas. + */ + virtual bool is_simplified_cond_processor(void *arg) { return false; } + + /** Processor used to check acceptability of an item in the defining + expression for a virtual column + + @param arg always ignored + + @retval 0 the item is accepted in the definition of a virtual column + @retval 1 otherwise + */ + struct vcol_func_processor_result + { + uint errors; /* Bits of possible errors */ + const char *name; /* Not supported function */ + Alter_info *alter_info; + vcol_func_processor_result() : + errors(0), name(NULL), alter_info(NULL) {} + }; + struct func_processor_rename + { + LEX_CSTRING db_name; + LEX_CSTRING table_name; + List<Create_field> fields; + }; + virtual bool check_vcol_func_processor(void *arg) + { + return mark_unsupported_function(full_name(), arg, VCOL_IMPOSSIBLE); + } + virtual bool check_field_expression_processor(void *arg) { return 0; } + virtual bool check_func_default_processor(void *arg) { return 0; } + /* + Check if an expression value has allowed arguments, like DATE/DATETIME + for date functions. Also used by partitioning code to reject + timezone-dependent expressions in a (sub)partitioning function. + */ + virtual bool check_valid_arguments_processor(void *arg) { return 0; } + virtual bool update_vcol_processor(void *arg) { return 0; } + virtual bool set_fields_as_dependent_processor(void *arg) { return 0; } + /* + Find if some of the key parts of table keys (the reference on table is + passed as an argument) participate in the expression. + If there is some, sets a bit for this key in the proper key map. + */ + virtual bool check_index_dependence(void *arg) { return 0; } + /*============== End of Item processor list ======================*/ + + /* + Given a condition P from the WHERE clause or from an ON expression of + the processed SELECT S and a set of join tables from S marked in the + parameter 'allowed'={T} a call of P->find_not_null_fields({T}) has to + find the set fields {F} of the tables from 'allowed' such that: + - each field from {F} is declared as nullable + - each record of table t from {T} that contains NULL as the value for at + at least one field from {F} can be ignored when building the result set + for S + It is assumed here that the condition P is conjunctive and all its column + references belong to T. + + Examples: + CREATE TABLE t1 (a int, b int); + CREATE TABLE t2 (a int, b int); + + SELECT * FROM t1,t2 WHERE t1.a=t2.a and t1.b > 5; + A call of find_not_null_fields() for the whole WHERE condition and {t1,t2} + should find {t1.a,t1.b,t2.a} + + SELECT * FROM t1 LEFT JOIN ON (t1.a=t2.a and t2.a > t2.b); + A call of find_not_null_fields() for the ON expression and {t2} + should find {t2.a,t2.b} + + The function returns TRUE if it succeeds to prove that all records of + a table from {T} can be ignored. Otherwise it always returns FALSE. + + Example: + SELECT * FROM t1,t2 WHERE t1.a=t2.a AND t2.a IS NULL; + A call of find_not_null_fields() for the WHERE condition and {t1,t2} + will return TRUE. + + It is assumed that the implementation of this virtual function saves + the info on the found set of fields in the structures associates with + tables from {T}. + */ + virtual bool find_not_null_fields(table_map allowed) { return false; } + + /* + Does not guarantee deep copy (depends on copy ctor). + See build_clone() for deep copy. + */ + virtual Item *get_copy(THD *thd)=0; + + bool cache_const_expr_analyzer(uchar **arg); + Item* cache_const_expr_transformer(THD *thd, uchar *arg); + + virtual Item* propagate_equal_fields(THD*, const Context &, COND_EQUAL *) + { + return this; + }; + + Item* propagate_equal_fields_and_change_item_tree(THD *thd, + const Context &ctx, + COND_EQUAL *cond, + Item **place); + + /* arg points to REPLACE_EQUAL_FIELD_ARG object */ + virtual Item *replace_equal_field(THD *thd, uchar *arg) { return this; } + + struct Collect_deps_prm + { + List<Item> *parameters; + /* unit from which we count nest_level */ + st_select_lex_unit *nest_level_base; + uint count; + int nest_level; + bool collect; + }; + + struct Check_table_name_prm + { + LEX_CSTRING db; + LEX_CSTRING table_name; + String field; + Check_table_name_prm(LEX_CSTRING _db, LEX_CSTRING _table_name) : + db(_db), table_name(_table_name) {} + }; + + /* + For SP local variable returns pointer to Item representing its + current value and pointer to current Item otherwise. + */ + virtual Item *this_item() { return this; } + virtual const Item *this_item() const { return this; } + + /* + For SP local variable returns address of pointer to Item representing its + current value and pointer passed via parameter otherwise. + */ + virtual Item **this_item_addr(THD *thd, Item **addr_arg) { return addr_arg; } + + // Row emulation + virtual uint cols() const { return 1; } + virtual Item* element_index(uint i) { return this; } + virtual Item** addr(uint i) { return 0; } + virtual bool check_cols(uint c); + bool check_type_traditional_scalar(const char *opname) const; + bool check_type_scalar(const char *opname) const; + bool check_type_or_binary(const char *opname, const Type_handler *handler) const; + bool check_type_general_purpose_string(const char *opname) const; + bool check_type_can_return_int(const char *opname) const; + bool check_type_can_return_decimal(const char *opname) const; + bool check_type_can_return_real(const char *opname) const; + bool check_type_can_return_str(const char *opname) const; + bool check_type_can_return_text(const char *opname) const; + bool check_type_can_return_date(const char *opname) const; + bool check_type_can_return_time(const char *opname) const; + // It is not row => null inside is impossible + virtual bool null_inside() { return 0; } + // used in row subselects to get value of elements + virtual void bring_value() {} + + const Type_handler *type_handler_long_or_longlong() const + { + return Type_handler::type_handler_long_or_longlong(max_char_length(), + unsigned_flag); + } + + /** + Create field for temporary table. + @param table Temporary table + @param [OUT] src Who created the fields + @param param Create parameters + @retval NULL (on error) + @retval a pointer to a newly create Field (on success) + */ + virtual Field *create_tmp_field_ex(MEM_ROOT *root, + TABLE *table, + Tmp_field_src *src, + const Tmp_field_param *param)= 0; + virtual Item_field *field_for_view_update() { return 0; } + + virtual Item *neg_transformer(THD *thd) { return NULL; } + virtual Item *update_value_transformer(THD *thd, uchar *select_arg) + { return this; } + virtual Item *expr_cache_insert_transformer(THD *thd, uchar *unused) + { return this; } + virtual Item *derived_field_transformer_for_having(THD *thd, uchar *arg) + { return this; } + virtual Item *derived_field_transformer_for_where(THD *thd, uchar *arg) + { return this; } + virtual Item *grouping_field_transformer_for_where(THD *thd, uchar *arg) + { return this; } + /* Now is not used. */ + virtual Item *in_subq_field_transformer_for_where(THD *thd, uchar *arg) + { return this; } + virtual Item *in_subq_field_transformer_for_having(THD *thd, uchar *arg) + { return this; } + virtual Item *in_predicate_to_in_subs_transformer(THD *thd, uchar *arg) + { return this; } + virtual Item *field_transformer_for_having_pushdown(THD *thd, uchar *arg) + { return this; } + virtual Item *multiple_equality_transformer(THD *thd, uchar *arg) + { return this; } + virtual bool expr_cache_is_needed(THD *) { return FALSE; } + virtual Item *safe_charset_converter(THD *thd, CHARSET_INFO *tocs); + bool needs_charset_converter(uint32 length, CHARSET_INFO *tocs) const + { + /* + This will return "true" if conversion happens: + - between two non-binary different character sets + - from "binary" to "unsafe" character set + (those that can have non-well-formed string) + - from "binary" to UCS2-alike character set with mbminlen>1, + when prefix left-padding is needed for an incomplete character: + binary 0xFF -> ucs2 0x00FF) + */ + if (!String::needs_conversion_on_storage(length, + collation.collation, tocs)) + return false; + /* + No needs to add converter if an "arg" is NUMERIC or DATETIME + value (which is pure ASCII) and at the same time target DTCollation + is ASCII-compatible. For example, no needs to rewrite: + SELECT * FROM t1 WHERE datetime_field = '2010-01-01'; + to + SELECT * FROM t1 WHERE CONVERT(datetime_field USING cs) = '2010-01-01'; + + TODO: avoid conversion of any values with + repertoire ASCII and 7bit-ASCII-compatible, + not only numeric/datetime origin. + */ + if (collation.derivation == DERIVATION_NUMERIC && + collation.repertoire == MY_REPERTOIRE_ASCII && + !(collation.collation->state & MY_CS_NONASCII) && + !(tocs->state & MY_CS_NONASCII)) + return false; + return true; + } + bool needs_charset_converter(CHARSET_INFO *tocs) + { + // Pass 1 as length to force conversion if tocs->mbminlen>1. + return needs_charset_converter(1, tocs); + } + Item *const_charset_converter(THD *thd, CHARSET_INFO *tocs, bool lossless, + const char *func_name); + Item *const_charset_converter(THD *thd, CHARSET_INFO *tocs, bool lossless) + { return const_charset_converter(thd, tocs, lossless, NULL); } + void delete_self() + { + cleanup(); + delete this; + } + + virtual const Item_const *get_item_const() const { return NULL; } + virtual Item_splocal *get_item_splocal() { return 0; } + virtual Rewritable_query_parameter *get_rewritable_query_parameter() + { return 0; } + + /* + Return Settable_routine_parameter interface of the Item. Return 0 + if this Item is not Settable_routine_parameter. + */ + virtual Settable_routine_parameter *get_settable_routine_parameter() + { + return 0; + } + + virtual Load_data_outvar *get_load_data_outvar() + { + return 0; + } + Load_data_outvar *get_load_data_outvar_or_error() + { + Load_data_outvar *dst= get_load_data_outvar(); + if (dst) + return dst; + my_error(ER_NONUPDATEABLE_COLUMN, MYF(0), name.str); + return NULL; + } + + /** + Test whether an expression is expensive to compute. Used during + optimization to avoid computing expensive expressions during this + phase. Also used to force temp tables when sorting on expensive + functions. + @todo + Normally we should have a method: + cost Item::execution_cost(), + where 'cost' is either 'double' or some structure of various cost + parameters. + + @note + This function is now used to prevent evaluation of expensive subquery + predicates during the optimization phase. It also prevents evaluation + of predicates that are not computable at this moment. + */ + virtual bool is_expensive() + { + if (is_expensive_cache < 0) + is_expensive_cache= walk(&Item::is_expensive_processor, 0, NULL); + return MY_TEST(is_expensive_cache); + } + String *check_well_formed_result(String *str, bool send_error= 0); + bool eq_by_collation(Item *item, bool binary_cmp, CHARSET_INFO *cs); + bool too_big_for_varchar() const + { return max_char_length() > CONVERT_IF_BIGGER_TO_BLOB; } + void fix_length_and_charset(uint32 max_char_length_arg, CHARSET_INFO *cs) + { + max_length= char_to_byte_length_safe(max_char_length_arg, cs->mbmaxlen); + collation.collation= cs; + } + void fix_char_length(size_t max_char_length_arg) + { + max_length= char_to_byte_length_safe(max_char_length_arg, + collation.collation->mbmaxlen); + } + /* + Return TRUE if the item points to a column of an outer-joined table. + */ + virtual bool is_outer_field() const { DBUG_ASSERT(is_fixed()); return FALSE; } + + /** + Checks if this item or any of its descendents contains a subquery. + This is a replacement of the former Item::has_subquery() and + Item::with_subselect. + */ + virtual bool with_subquery() const { DBUG_ASSERT(is_fixed()); return false; } + + virtual bool with_sum_func() const { return false; } + virtual With_sum_func_cache* get_with_sum_func_cache() { return NULL; } + + Item* set_expr_cache(THD *thd); + + virtual Item_equal *get_item_equal() { return NULL; } + virtual void set_item_equal(Item_equal *item_eq) {}; + virtual Item_equal *find_item_equal(COND_EQUAL *cond_equal) { return NULL; } + /** + Set the join tab index to the minimal (left-most) JOIN_TAB to which this + Item is attached. The number is an index is depth_first_tab() traversal + order. + */ + virtual void set_join_tab_idx(uint join_tab_idx_arg) + { + if (join_tab_idx_arg < join_tab_idx) + join_tab_idx= join_tab_idx_arg; + } + uint get_join_tab_idx() const { return join_tab_idx; } + + table_map view_used_tables(TABLE_LIST *view) + { + view->view_used_tables= 0; + walk(&Item::view_used_tables_processor, 0, view); + return view->view_used_tables; + } + + /** + Collect and add to the list cache parameters for this Item. + + @note Now implemented only for subqueries and in_optimizer, + if we need it for general function then this method should + be defined for Item_func. + */ + virtual void get_cache_parameters(List<Item> ¶meters) { }; + + virtual void mark_as_condition_AND_part(TABLE_LIST *embedding) {}; + + /* how much position should be reserved for Exists2In transformation */ + virtual uint exists2in_reserved_items() { return 0; }; + + virtual Item *neg(THD *thd); + + /** + Inform the item that it is located under a NOT, which is a top-level item. + */ + virtual void under_not(Item_func_not * upper + __attribute__((unused))) {}; + /* + If Item_field is wrapped in Item_direct_wrep remove this Item_direct_ref + wrapper. + */ + virtual Item *remove_item_direct_ref() { return this; } + + + void register_in(THD *thd); + + bool depends_only_on(table_map view_map) + { return marker & FULL_EXTRACTION_FL; } + int get_extraction_flag() + { return marker & EXTRACTION_MASK; } + void set_extraction_flag(int flags) + { + marker &= ~EXTRACTION_MASK; + marker|= flags; + } + void clear_extraction_flag() + { + marker &= ~EXTRACTION_MASK; + } + void check_pushable_cond(Pushdown_checker excl_dep_func, uchar *arg); + bool pushable_cond_checker_for_derived(uchar *arg) + { + return excl_dep_on_table(*((table_map *)arg)); + } + bool pushable_cond_checker_for_subquery(uchar *arg) + { + DBUG_ASSERT(((Item*) arg)->get_IN_subquery()); + return excl_dep_on_in_subq_left_part(((Item*)arg)->get_IN_subquery()); + } + Item *build_pushable_cond(THD *thd, + Pushdown_checker checker, + uchar *arg); + /* + Checks if this item depends only on the arg table + */ + bool pushable_equality_checker_for_derived(uchar *arg) + { + return (used_tables() == *((table_map *)arg)); + } + /* + Checks if this item consists in the left part of arg IN subquery predicate + */ + bool pushable_equality_checker_for_subquery(uchar *arg); +}; + +MEM_ROOT *get_thd_memroot(THD *thd); + +template <class T> +inline Item* get_item_copy (THD *thd, T* item) +{ + Item *copy= new (get_thd_memroot(thd)) T(*item); + if (likely(copy)) + copy->register_in(thd); + return copy; +} + + +#ifndef DBUG_OFF +/** + A helper class to print the data type and the value for an Item + in debug builds. +*/ +class DbugStringItemTypeValue: public StringBuffer<128> +{ +public: + DbugStringItemTypeValue(THD *thd, const Item *item) + { + append('('); + append(item->type_handler()->name().ptr()); + append(')'); + const_cast<Item*>(item)->print(this, QT_EXPLAIN); + /* Append end \0 to allow usage of c_ptr() */ + append('\0'); + str_length--; + } +}; +#endif + +class With_sum_func_cache +{ +protected: + bool m_with_sum_func; // True if the owner item contains a sum func +public: + With_sum_func_cache() + :m_with_sum_func(false) + { } + With_sum_func_cache(const Item *a) + :m_with_sum_func(a->with_sum_func()) + { } + With_sum_func_cache(const Item *a, const Item *b) + :m_with_sum_func(a->with_sum_func() || b->with_sum_func()) + { } + With_sum_func_cache(const Item *a, const Item *b, const Item *c) + :m_with_sum_func(a->with_sum_func() || b->with_sum_func() || + c->with_sum_func()) + { } + With_sum_func_cache(const Item *a, const Item *b, const Item *c, + const Item *d) + :m_with_sum_func(a->with_sum_func() || b->with_sum_func() || + c->with_sum_func() || d->with_sum_func()) + { } + With_sum_func_cache(const Item *a, const Item *b, const Item *c, + const Item *d, const Item *e) + :m_with_sum_func(a->with_sum_func() || b->with_sum_func() || + c->with_sum_func() || d->with_sum_func() || + e->with_sum_func()) + { } + void set_with_sum_func() { m_with_sum_func= true; } + void reset_with_sum_func() { m_with_sum_func= false; } + void copy_with_sum_func(const Item *item) + { + m_with_sum_func= item->with_sum_func(); + } + void join_with_sum_func(const Item *item) + { + m_with_sum_func|= item->with_sum_func(); + } +}; + + +/* + This class is a replacement for the former member Item::with_subselect. + Determines if the descendant Item is a subselect or some of + its arguments is or contains a subselect. +*/ +class With_subquery_cache +{ +protected: + bool m_with_subquery; +public: + With_subquery_cache(): m_with_subquery(false) { } + void join(const Item *item) { m_with_subquery|= item->with_subquery(); } +}; + + +/** + Compare two Items for List<Item>::add_unique() +*/ + +bool cmp_items(Item *a, Item *b); + + +/** + Array of items, e.g. function or aggerate function arguments. +*/ +class Item_args +{ +protected: + Item **args, *tmp_arg[2]; + uint arg_count; + void set_arguments(THD *thd, List<Item> &list); + bool walk_args(Item_processor processor, bool walk_subquery, void *arg) + { + for (uint i= 0; i < arg_count; i++) + { + if (args[i]->walk(processor, walk_subquery, arg)) + return true; + } + return false; + } + bool transform_args(THD *thd, Item_transformer transformer, uchar *arg); + void propagate_equal_fields(THD *, const Item::Context &, COND_EQUAL *); + bool excl_dep_on_table(table_map tab_map) + { + for (uint i= 0; i < arg_count; i++) + { + if (args[i]->const_item()) + continue; + if (!args[i]->excl_dep_on_table(tab_map)) + return false; + } + return true; + } + bool excl_dep_on_grouping_fields(st_select_lex *sel); + bool eq(const Item_args *other, bool binary_cmp) const + { + for (uint i= 0; i < arg_count ; i++) + { + if (!args[i]->eq(other->args[i], binary_cmp)) + return false; + } + return true; + } + bool excl_dep_on_in_subq_left_part(Item_in_subselect *subq_pred) + { + for (uint i= 0; i < arg_count; i++) + { + if (args[i]->const_item()) + continue; + if (!args[i]->excl_dep_on_in_subq_left_part(subq_pred)) + return false; + } + return true; + } +public: + Item_args(void) + :args(NULL), arg_count(0) + { } + Item_args(Item *a) + :args(tmp_arg), arg_count(1) + { + args[0]= a; + } + Item_args(Item *a, Item *b) + :args(tmp_arg), arg_count(2) + { + args[0]= a; args[1]= b; + } + Item_args(THD *thd, Item *a, Item *b, Item *c) + { + arg_count= 0; + if (likely((args= (Item**) thd_alloc(thd, sizeof(Item*) * 3)))) + { + arg_count= 3; + args[0]= a; args[1]= b; args[2]= c; + } + } + Item_args(THD *thd, Item *a, Item *b, Item *c, Item *d) + { + arg_count= 0; + if (likely((args= (Item**) thd_alloc(thd, sizeof(Item*) * 4)))) + { + arg_count= 4; + args[0]= a; args[1]= b; args[2]= c; args[3]= d; + } + } + Item_args(THD *thd, Item *a, Item *b, Item *c, Item *d, Item* e) + { + arg_count= 5; + if (likely((args= (Item**) thd_alloc(thd, sizeof(Item*) * 5)))) + { + arg_count= 5; + args[0]= a; args[1]= b; args[2]= c; args[3]= d; args[4]= e; + } + } + Item_args(THD *thd, List<Item> &list) + { + set_arguments(thd, list); + } + Item_args(THD *thd, const Item_args *other); + bool alloc_arguments(THD *thd, uint count); + void add_argument(Item *item) + { + args[arg_count++]= item; + } + /** + Extract row elements from the given position. + For example, for this input: (1,2),(3,4),(5,6) + pos=0 will extract (1,3,5) + pos=1 will extract (2,4,6) + @param thd - current thread, to allocate memory on its mem_root + @param rows - an array of compatible ROW-type items + @param pos - the element position to extract + */ + bool alloc_and_extract_row_elements(THD *thd, const Item_args *rows, uint pos) + { + DBUG_ASSERT(rows->argument_count() > 0); + DBUG_ASSERT(rows->arguments()[0]->cols() > pos); + if (alloc_arguments(thd, rows->argument_count())) + return true; + for (uint i= 0; i < rows->argument_count(); i++) + { + DBUG_ASSERT(rows->arguments()[0]->cols() == rows->arguments()[i]->cols()); + Item *arg= rows->arguments()[i]->element_index(pos); + add_argument(arg); + } + DBUG_ASSERT(argument_count() == rows->argument_count()); + return false; + } + inline Item **arguments() const { return args; } + inline uint argument_count() const { return arg_count; } + inline void remove_arguments() { arg_count=0; } + Sql_mode_dependency value_depends_on_sql_mode_bit_or() const; +}; + + +/* + Class to be used to enumerate all field references in an item tree. This + includes references to outside but not fields of the tables within a + subquery. + Suggested usage: + + class My_enumerator : public Field_enumerator + { + virtual void visit_field() { ... your actions ...} + } + + My_enumerator enumerator; + item->walk(Item::enumerate_field_refs_processor, ...,&enumerator); + + This is similar to Visitor pattern. +*/ + +class Field_enumerator +{ +public: + virtual void visit_field(Item_field *field)= 0; + virtual ~Field_enumerator() {}; /* purecov: inspected */ + Field_enumerator() {} /* Remove gcc warning */ +}; + +class Item_string; + + +class Item_fixed_hybrid: public Item +{ +public: + bool fixed; // If item was fixed with fix_fields +public: + Item_fixed_hybrid(THD *thd): Item(thd), fixed(false) + { } + Item_fixed_hybrid(THD *thd, Item_fixed_hybrid *item) + :Item(thd, item), fixed(item->fixed) + { } + bool fix_fields(THD *thd, Item **ref) + { + DBUG_ASSERT(!fixed); + fixed= true; + return false; + } + void cleanup() + { + Item::cleanup(); + fixed= false; + } + void quick_fix_field() { fixed= true; } + void unfix_fields() { fixed= false; } + bool is_fixed() const { return fixed; } +}; + + +/** + A common class for Item_basic_constant and Item_param +*/ +class Item_basic_value :public Item, + public Item_const +{ +protected: + // Value metadata, e.g. to make string processing easier + class Metadata: private MY_STRING_METADATA + { + public: + Metadata(const String *str) + { + my_string_metadata_get(this, str->charset(), str->ptr(), str->length()); + } + Metadata(const String *str, my_repertoire_t repertoire_arg) + { + MY_STRING_METADATA::repertoire= repertoire_arg; + MY_STRING_METADATA::char_length= str->numchars(); + } + my_repertoire_t repertoire() const + { + return MY_STRING_METADATA::repertoire; + } + size_t char_length() const { return MY_STRING_METADATA::char_length; } + }; + void fix_charset_and_length(CHARSET_INFO *cs, + Derivation dv, Metadata metadata) + { + /* + We have to have a different max_length than 'length' here to + ensure that we get the right length if we do use the item + to create a new table. In this case max_length must be the maximum + number of chars for a string of this type because we in Create_field:: + divide the max_length with mbmaxlen). + */ + collation.set(cs, dv, metadata.repertoire()); + fix_char_length(metadata.char_length()); + decimals= NOT_FIXED_DEC; + } + void fix_charset_and_length_from_str_value(const String &str, Derivation dv) + { + fix_charset_and_length(str.charset(), dv, Metadata(&str)); + } + Item_basic_value(THD *thd): Item(thd) {} +public: + Field *create_tmp_field_ex(MEM_ROOT *root, + TABLE *table, Tmp_field_src *src, + const Tmp_field_param *param) override + { + + /* + create_tmp_field_ex() for this type of Items is called for: + - CREATE TABLE ... SELECT + - In ORDER BY: SELECT max(a) FROM t1 GROUP BY a ORDER BY 'const'; + - In CURSORS: + DECLARE c CURSOR FOR SELECT 'test'; + OPEN c; + */ + return tmp_table_field_from_field_type_maybe_null(root, + table, src, param, + type() == Item::NULL_ITEM); + } + bool eq(const Item *item, bool binary_cmp) const override; + const Type_all_attributes *get_type_all_attributes_from_const() const + override + { return this; } +}; + + +class Item_basic_constant :public Item_basic_value +{ +public: + Item_basic_constant(THD *thd): Item_basic_value(thd) {}; + bool check_vcol_func_processor(void *arg) { return false; } + const Item_const *get_item_const() const { return this; } + virtual Item_basic_constant *make_string_literal_concat(THD *thd, + const LEX_CSTRING *) + { + DBUG_ASSERT(0); + return this; + } +}; + + +/***************************************************************************** + The class is a base class for representation of stored routine variables in + the Item-hierarchy. There are the following kinds of SP-vars: + - local variables (Item_splocal); + - CASE expression (Item_case_expr); +*****************************************************************************/ + +class Item_sp_variable :public Item_fixed_hybrid +{ +protected: + /* + THD, which is stored in fix_fields() and is used in this_item() to avoid + current_thd use. + */ + THD *m_thd; + + bool fix_fields_from_item(THD *thd, Item **, const Item *); +public: + LEX_CSTRING m_name; + +public: +#ifdef DBUG_ASSERT_EXISTS + /* + Routine to which this Item_splocal belongs. Used for checking if correct + runtime context is used for variable handling. + */ + const sp_head *m_sp; +#endif + +public: + Item_sp_variable(THD *thd, const LEX_CSTRING *sp_var_name); + +public: + bool fix_fields(THD *thd, Item **) override= 0; + + double val_real() override; + longlong val_int() override; + String *val_str(String *sp) override; + my_decimal *val_decimal(my_decimal *decimal_value) override; + bool get_date(THD *thd, MYSQL_TIME *ltime, date_mode_t fuzzydate) override; + bool val_native(THD *thd, Native *to) override; + bool is_null() override; + +public: + void make_send_field(THD *thd, Send_field *field) override; + + bool const_item() const override { return true; } + + Field *create_tmp_field_ex(MEM_ROOT *root, + TABLE *table, Tmp_field_src *src, + const Tmp_field_param *param) override + { + return create_tmp_field_ex_simple(root, table, src, param); + } + inline int save_in_field(Field *field, bool no_conversions) override; + inline bool send(Protocol *protocol, st_value *buffer) override; + bool check_vcol_func_processor(void *arg) override + { + return mark_unsupported_function(m_name.str, arg, VCOL_IMPOSSIBLE); + } +}; + +/***************************************************************************** + Item_sp_variable inline implementation. +*****************************************************************************/ + +inline int Item_sp_variable::save_in_field(Field *field, bool no_conversions) +{ + return this_item()->save_in_field(field, no_conversions); +} + +inline bool Item_sp_variable::send(Protocol *protocol, st_value *buffer) +{ + return this_item()->send(protocol, buffer); +} + + +/***************************************************************************** + A reference to local SP variable (incl. reference to SP parameter), used in + runtime. +*****************************************************************************/ + +class Item_splocal :public Item_sp_variable, + private Settable_routine_parameter, + public Rewritable_query_parameter, + public Type_handler_hybrid_field_type +{ +protected: + const Sp_rcontext_handler *m_rcontext_handler; + + uint m_var_idx; + + Type m_type; + + bool append_value_for_log(THD *thd, String *str); + + sp_rcontext *get_rcontext(sp_rcontext *local_ctx) const; + Item_field *get_variable(sp_rcontext *ctx) const; + +public: + Item_splocal(THD *thd, const Sp_rcontext_handler *rh, + const LEX_CSTRING *sp_var_name, uint sp_var_idx, + const Type_handler *handler, + uint pos_in_q= 0, uint len_in_q= 0); + + bool fix_fields(THD *, Item **) override; + Item *this_item() override; + const Item *this_item() const override; + Item **this_item_addr(THD *thd, Item **) override; + + void print(String *str, enum_query_type query_type) override; + +public: + inline const LEX_CSTRING *my_name() const; + + inline uint get_var_idx() const; + + Type type() const override { return m_type; } + const Type_handler *type_handler() const override + { return Type_handler_hybrid_field_type::type_handler(); } + uint cols() const override { return this_item()->cols(); } + Item* element_index(uint i) override + { return this_item()->element_index(i); } + Item** addr(uint i) override { return this_item()->addr(i); } + bool check_cols(uint c) override; + +private: + bool set_value(THD *thd, sp_rcontext *ctx, Item **it) override; + +public: + Item_splocal *get_item_splocal() override { return this; } + + Rewritable_query_parameter *get_rewritable_query_parameter() override + { return this; } + + Settable_routine_parameter *get_settable_routine_parameter() override + { return this; } + + bool append_for_log(THD *thd, String *str) override; + + Item *get_copy(THD *) override { return nullptr; } + + /* + Override the inherited create_field_for_create_select(), + because we want to preserve the exact data type for: + DECLARE a1 INT; + DECLARE a2 TYPE OF t1.a2; + CREATE TABLE t1 AS SELECT a1, a2; + The inherited implementation would create a column + based on result_type(), which is less exact. + */ + Field *create_field_for_create_select(MEM_ROOT *root, TABLE *table) override + { return create_table_field_from_handler(root, table); } + + bool is_valid_limit_clause_variable_with_error() const + { + /* + In case if the variable has an anchored data type, e.g.: + DECLARE a TYPE OF t1.a; + type_handler() is set to &type_handler_null and this + function detects such variable as not valid in LIMIT. + */ + if (type_handler()->is_limit_clause_valid_type()) + return true; + my_error(ER_WRONG_SPVAR_TYPE_IN_LIMIT, MYF(0)); + return false; + } +}; + + +/** + An Item_splocal variant whose data type becomes known only at + sp_rcontext creation time, e.g. "DECLARE var1 t1.col1%TYPE". +*/ +class Item_splocal_with_delayed_data_type: public Item_splocal +{ +public: + Item_splocal_with_delayed_data_type(THD *thd, + const Sp_rcontext_handler *rh, + const LEX_CSTRING *sp_var_name, + uint sp_var_idx, + uint pos_in_q, uint len_in_q) + :Item_splocal(thd, rh, sp_var_name, sp_var_idx, &type_handler_null, + pos_in_q, len_in_q) + { } +}; + + +/** + SP variables that are fields of a ROW. + DELCARE r ROW(a INT,b INT); + SELECT r.a; -- This is handled by Item_splocal_row_field +*/ +class Item_splocal_row_field :public Item_splocal +{ +protected: + LEX_CSTRING m_field_name; + uint m_field_idx; + bool set_value(THD *thd, sp_rcontext *ctx, Item **it) override; +public: + Item_splocal_row_field(THD *thd, + const Sp_rcontext_handler *rh, + const LEX_CSTRING *sp_var_name, + const LEX_CSTRING *sp_field_name, + uint sp_var_idx, uint sp_field_idx, + const Type_handler *handler, + uint pos_in_q= 0, uint len_in_q= 0) + :Item_splocal(thd, rh, sp_var_name, sp_var_idx, handler, pos_in_q, len_in_q), + m_field_name(*sp_field_name), + m_field_idx(sp_field_idx) + { } + bool fix_fields(THD *thd, Item **) override; + Item *this_item() override; + const Item *this_item() const override; + Item **this_item_addr(THD *thd, Item **) override; + bool append_for_log(THD *thd, String *str) override; + void print(String *str, enum_query_type query_type) override; +}; + + +class Item_splocal_row_field_by_name :public Item_splocal_row_field +{ + bool set_value(THD *thd, sp_rcontext *ctx, Item **it) override; +public: + Item_splocal_row_field_by_name(THD *thd, + const Sp_rcontext_handler *rh, + const LEX_CSTRING *sp_var_name, + const LEX_CSTRING *sp_field_name, + uint sp_var_idx, + const Type_handler *handler, + uint pos_in_q= 0, uint len_in_q= 0) + :Item_splocal_row_field(thd, rh, sp_var_name, sp_field_name, + sp_var_idx, 0 /* field index will be set later */, + handler, pos_in_q, len_in_q) + { } + bool fix_fields(THD *thd, Item **it) override; + void print(String *str, enum_query_type query_type) override; +}; + + +/***************************************************************************** + Item_splocal inline implementation. +*****************************************************************************/ + +inline const LEX_CSTRING *Item_splocal::my_name() const +{ + return &m_name; +} + +inline uint Item_splocal::get_var_idx() const +{ + return m_var_idx; +} + +/***************************************************************************** + A reference to case expression in SP, used in runtime. +*****************************************************************************/ + +class Item_case_expr :public Item_sp_variable +{ +public: + Item_case_expr(THD *thd, uint case_expr_id); + +public: + bool fix_fields(THD *thd, Item **) override; + Item *this_item() override; + const Item *this_item() const override; + Item **this_item_addr(THD *thd, Item **) override; + + Type type() const override; + const Type_handler *type_handler() const override + { return this_item()->type_handler(); } + +public: + /* + NOTE: print() is intended to be used from views and for debug. + Item_case_expr can not occur in views, so here it is only for debug + purposes. + */ + void print(String *str, enum_query_type query_type) override; + Item *get_copy(THD *) override { return nullptr; } + +private: + uint m_case_expr_id; +}; + +/***************************************************************************** + Item_case_expr inline implementation. +*****************************************************************************/ + +inline enum Item::Type Item_case_expr::type() const +{ + return this_item()->type(); +} + +/* + NAME_CONST(given_name, const_value). + This 'function' has all properties of the supplied const_value (which is + assumed to be a literal constant), and the name given_name. + + This is used to replace references to SP variables when we write PROCEDURE + statements into the binary log. + + TODO + Together with Item_splocal and Item::this_item() we can actually extract + common a base of this class and Item_splocal. Maybe it is possible to + extract a common base with class Item_ref, too. +*/ + +class Item_name_const : public Item_fixed_hybrid +{ + Item *value_item; + Item *name_item; +public: + Item_name_const(THD *thd, Item *name_arg, Item *val); + + bool fix_fields(THD *, Item **) override; + + Type type() const override; + double val_real() override; + longlong val_int() override; + String *val_str(String *sp) override; + my_decimal *val_decimal(my_decimal *) override; + bool get_date(THD *thd, MYSQL_TIME *ltime, date_mode_t fuzzydate) override; + bool val_native(THD *thd, Native *to) override; + bool is_null() override; + void print(String *str, enum_query_type query_type) override; + + const Type_handler *type_handler() const override + { + return value_item->type_handler(); + } + + bool const_item() const override { return true; } + + Field *create_tmp_field_ex(MEM_ROOT *root, + TABLE *table, Tmp_field_src *src, + const Tmp_field_param *param) override + { + /* + We can get to here when using a CURSOR for a query with NAME_CONST(): + DECLARE c CURSOR FOR SELECT NAME_CONST('x','y') FROM t1; + OPEN c; + */ + return tmp_table_field_from_field_type_maybe_null(root, table, src, param, + type() == Item::NULL_ITEM); + } + int save_in_field(Field *field, bool no_conversions) override + { + return value_item->save_in_field(field, no_conversions); + } + + bool send(Protocol *protocol, st_value *buffer) override + { + return value_item->send(protocol, buffer); + } + bool check_vcol_func_processor(void *arg) override + { + return mark_unsupported_function("name_const()", arg, VCOL_IMPOSSIBLE); + } + Item *get_copy(THD *thd) override + { return get_item_copy<Item_name_const>(thd, this); } +}; + + +class Item_literal: public Item_basic_constant +{ +public: + Item_literal(THD *thd): Item_basic_constant(thd) + { } + Type type() const override { return CONST_ITEM; } + bool check_partition_func_processor(void *) override { return false;} + bool const_item() const override { return true; } + bool basic_const_item() const override { return true; } +}; + + +class Item_num: public Item_literal +{ +public: + Item_num(THD *thd): Item_literal(thd) { collation= DTCollation_numeric(); } + Item *safe_charset_converter(THD *thd, CHARSET_INFO *tocs) override; + bool get_date(THD *thd, MYSQL_TIME *ltime, date_mode_t fuzzydate) override + { + return type_handler()->Item_get_date_with_warn(thd, this, ltime, fuzzydate); + } +}; + +#define NO_CACHED_FIELD_INDEX ((uint)(-1)) + +class st_select_lex; + + +class Item_result_field :public Item_fixed_hybrid /* Item with result field */ +{ +protected: + Field *create_tmp_field_ex_from_handler(MEM_ROOT *root, TABLE *table, + Tmp_field_src *src, + const Tmp_field_param *param, + const Type_handler *h); +public: + Field *result_field; /* Save result here */ + Item_result_field(THD *thd): Item_fixed_hybrid(thd), result_field(0) {} + // Constructor used for Item_sum/Item_cond_and/or (see Item comment) + Item_result_field(THD *thd, Item_result_field *item): + Item_fixed_hybrid(thd, item), result_field(item->result_field) + {} + ~Item_result_field() {} /* Required with gcc 2.95 */ + Field *get_tmp_table_field() override { return result_field; } + Field *create_tmp_field_ex(MEM_ROOT *root, TABLE *table, Tmp_field_src *src, + const Tmp_field_param *param) override + { + DBUG_ASSERT(fixed); + const Type_handler *h= type_handler()->type_handler_for_tmp_table(this); + return create_tmp_field_ex_from_handler(root, table, src, param, h); + } + void get_tmp_field_src(Tmp_field_src *src, const Tmp_field_param *param); + /* + This implementation of used_tables() used by Item_avg_field and + Item_variance_field which work when only temporary table left, so theu + return table map of the temporary table. + */ + table_map used_tables() const override { return 1; } + bool is_result_field() override { return true; } + void save_in_result_field(bool no_conversions) override + { + save_in_field(result_field, no_conversions); + } + void cleanup() override; + bool check_vcol_func_processor(void *) override { return false; } +}; + + +class Item_ident :public Item_result_field +{ +protected: + /* + We have to store initial values of db_name, table_name and field_name + to be able to restore them during cleanup() because they can be + updated during fix_fields() to values from Field object and life-time + of those is shorter than life-time of Item_field. + */ + LEX_CSTRING orig_db_name; + LEX_CSTRING orig_table_name; + LEX_CSTRING orig_field_name; + + void undeclared_spvar_error() const; + +public: + Name_resolution_context *context; + LEX_CSTRING db_name; + LEX_CSTRING table_name; + LEX_CSTRING field_name; + bool alias_name_used; /* true if item was resolved against alias */ + /* + Cached value of index for this field in table->field array, used by prep. + stmts for speeding up their re-execution. Holds NO_CACHED_FIELD_INDEX + if index value is not known. + */ + uint cached_field_index; + /* + Cached pointer to table which contains this field, used for the same reason + by prep. stmt. too in case then we have not-fully qualified field. + 0 - means no cached value. + */ + TABLE_LIST *cached_table; + st_select_lex *depended_from; + /* + Some Items resolved in another select should not be marked as dependency + of the subquery where they are. During normal name resolution, we check + this. Stored procedures and prepared statements first try to resolve an + ident item using a cached table reference and field position from the + previous query execution (cached_table/cached_field_index). If the + tables were not changed, the ident matches the table/field, and we have + faster resolution of the ident without looking through all tables and + fields in the query. But in this case, we can not check all conditions + about this ident item dependency, so we should cache the condition in + this variable. + */ + bool can_be_depended; + Item_ident(THD *thd, Name_resolution_context *context_arg, + const LEX_CSTRING &db_name_arg, const LEX_CSTRING &table_name_arg, + const LEX_CSTRING &field_name_arg); + Item_ident(THD *thd, Item_ident *item); + Item_ident(THD *thd, TABLE_LIST *view_arg, const LEX_CSTRING &field_name_arg); + const char *full_name() const override; + void cleanup() override; + st_select_lex *get_depended_from() const; + bool remove_dependence_processor(void * arg) override; + void print(String *str, enum_query_type query_type) override; + bool change_context_processor(void *cntx) override + { context= (Name_resolution_context *)cntx; return FALSE; } + /** + Collect outer references + */ + bool collect_outer_ref_processor(void *arg) override; + friend bool insert_fields(THD *thd, Name_resolution_context *context, + const char *db_name, + const char *table_name, List_iterator<Item> *it, + bool any_privileges, bool returning_field); +}; + + +class Item_field :public Item_ident, + public Load_data_outvar +{ +protected: + void set_field(Field *field); +public: + Field *field; + Item_equal *item_equal; + /* + if any_privileges set to TRUE then here real effective privileges will + be stored + */ + privilege_t have_privileges; + /* field need any privileges (for VIEW creation) */ + bool any_privileges; + Item_field(THD *thd, Name_resolution_context *context_arg, + const LEX_CSTRING &db_arg, const LEX_CSTRING &table_name_arg, + const LEX_CSTRING &field_name_arg); + Item_field(THD *thd, Name_resolution_context *context_arg, + const LEX_CSTRING &field_name_arg) + :Item_field(thd, context_arg, null_clex_str, null_clex_str, field_name_arg) + { } + Item_field(THD *thd, Name_resolution_context *context_arg) + :Item_field(thd, context_arg, null_clex_str, null_clex_str, null_clex_str) + { } + /* + Constructor needed to process subselect with temporary tables (see Item) + */ + Item_field(THD *thd, Item_field *item); + /* + Constructor used inside setup_wild(), ensures that field, table, + and database names will live as long as Item_field (this is important + in prepared statements). + */ + Item_field(THD *thd, Name_resolution_context *context_arg, Field *field); + /* + If this constructor is used, fix_fields() won't work, because + db_name, table_name and column_name are unknown. It's necessary to call + reset_field() before fix_fields() for all fields created this way. + */ + Item_field(THD *thd, Field *field); + Type type() const override { return FIELD_ITEM; } + bool eq(const Item *item, bool binary_cmp) const override; + double val_real() override; + longlong val_int() override; + my_decimal *val_decimal(my_decimal *) override; + String *val_str(String*) override; + void save_result(Field *to) override; + double val_result() override; + longlong val_int_result() override; + bool val_native(THD *thd, Native *to) override; + bool val_native_result(THD *thd, Native *to) override; + String *str_result(String* tmp) override; + my_decimal *val_decimal_result(my_decimal *) override; + bool val_bool_result() override; + bool is_null_result() override; + bool is_json_type() override; + bool send(Protocol *protocol, st_value *buffer) override; + Load_data_outvar *get_load_data_outvar() override { return this; } + bool load_data_set_null(THD *thd, const Load_data_param *param) override + { + return field->load_data_set_null(thd); + } + bool load_data_set_value(THD *thd, const char *pos, uint length, + const Load_data_param *param) override + { + field->load_data_set_value(pos, length, param->charset()); + return false; + } + bool load_data_set_no_data(THD *thd, const Load_data_param *param) override; + void load_data_print_for_log_event(THD *thd, String *to) const override; + bool load_data_add_outvar(THD *thd, Load_data_param *param) const override + { + return param->add_outvar_field(thd, field); + } + uint load_data_fixed_length() const override + { + return field->field_length; + } + void reset_field(Field *f); + bool fix_fields(THD *, Item **) override; + void fix_after_pullout(st_select_lex *new_parent, Item **ref, bool merge) + override; + void make_send_field(THD *thd, Send_field *tmp_field) override; + int save_in_field(Field *field,bool no_conversions) override; + void save_org_in_field(Field *field, fast_field_copier optimizer_data) + override; + fast_field_copier setup_fast_field_copier(Field *field) override; + table_map used_tables() const override; + table_map all_used_tables() const override; + const Type_handler *type_handler() const override + { + const Type_handler *handler= field->type_handler(); + return handler->type_handler_for_item_field(); + } + const Type_handler *real_type_handler() const override + { + if (field->is_created_from_null_item) + return &type_handler_null; + return field->type_handler(); + } + Field *create_tmp_field_from_item_field(MEM_ROOT *root, TABLE *new_table, + Item_ref *orig_item, + const Tmp_field_param *param); + Field *create_tmp_field_ex(MEM_ROOT *root, + TABLE *table, Tmp_field_src *src, + const Tmp_field_param *param) override; + const TYPELIB *get_typelib() const override { return field->get_typelib(); } + enum_monotonicity_info get_monotonicity_info() const override + { + return MONOTONIC_STRICT_INCREASING; + } + Sql_mode_dependency value_depends_on_sql_mode() const override + { + return Sql_mode_dependency(0, field->value_depends_on_sql_mode()); + } + longlong val_int_endpoint(bool left_endp, bool *incl_endp) override; + bool get_date(THD *thd, MYSQL_TIME *ltime, date_mode_t fuzzydate) override; + bool get_date_result(THD *thd, MYSQL_TIME *ltime,date_mode_t fuzzydate) + override; + longlong val_datetime_packed(THD *thd) override; + longlong val_time_packed(THD *thd) override; + bool is_null() override { return field->is_null(); } + void update_null_value() override; + void update_table_bitmaps() + { + if (field && field->table) + { + TABLE *tab= field->table; + tab->covering_keys.intersect(field->part_of_key); + if (tab->read_set) + tab->mark_column_with_deps(field); + } + } + void update_used_tables() override + { + update_table_bitmaps(); + } + COND *build_equal_items(THD *thd, COND_EQUAL *inherited, + bool link_item_fields, + COND_EQUAL **cond_equal_ref) override + { + /* + normilize_cond() replaced all conditions of type + WHERE/HAVING field + to: + WHERE/HAVING field<>0 + By the time of a build_equal_items() call, all such conditions should + already be replaced. No Item_field are possible. + Note, some Item_field derivants are still possible. + Item_insert_value: + SELECT * FROM t1 WHERE VALUES(a); + Item_default_value: + SELECT * FROM t1 WHERE DEFAULT(a); + */ + DBUG_ASSERT(type() != FIELD_ITEM); + return Item_ident::build_equal_items(thd, inherited, link_item_fields, + cond_equal_ref); + } + bool is_result_field() override { return false; } + void save_in_result_field(bool no_conversions) override; + Item *get_tmp_table_item(THD *thd) override; + bool find_not_null_fields(table_map allowed) override; + bool collect_item_field_processor(void * arg) override; + bool unknown_splocal_processor(void *arg) override; + bool add_field_to_set_processor(void * arg) override; + bool find_item_in_field_list_processor(void *arg) override; + bool register_field_in_read_map(void *arg) override; + bool register_field_in_write_map(void *arg) override; + bool register_field_in_bitmap(void *arg) override; + bool check_partition_func_processor(void *) override {return false;} + bool post_fix_fields_part_expr_processor(void *bool_arg) override; + bool check_valid_arguments_processor(void *bool_arg) override; + bool check_field_expression_processor(void *arg) override; + bool enumerate_field_refs_processor(void *arg) override; + bool update_table_bitmaps_processor(void *arg) override; + bool switch_to_nullable_fields_processor(void *arg) override; + bool update_vcol_processor(void *arg) override; + bool rename_fields_processor(void *arg) override; + bool check_vcol_func_processor(void *arg) override; + bool set_fields_as_dependent_processor(void *arg) override + { + if (!(used_tables() & OUTER_REF_TABLE_BIT)) + { + depended_from= (st_select_lex *) arg; + item_equal= NULL; + } + return 0; + } + bool check_table_name_processor(void *arg) override + { + Check_table_name_prm &p= *static_cast<Check_table_name_prm*>(arg); + if (!field && p.table_name.length && table_name.length) + { + DBUG_ASSERT(p.db.length); + if ((db_name.length && + my_strcasecmp(table_alias_charset, p.db.str, db_name.str)) || + my_strcasecmp(table_alias_charset, p.table_name.str, table_name.str)) + { + print(&p.field, (enum_query_type) (QT_ITEM_ORIGINAL_FUNC_NULLIF | + QT_NO_DATA_EXPANSION | + QT_TO_SYSTEM_CHARSET)); + return true; + } + } + return false; + } + void cleanup() override; + Item_equal *get_item_equal() override { return item_equal; } + void set_item_equal(Item_equal *item_eq) override { item_equal= item_eq; } + Item_equal *find_item_equal(COND_EQUAL *cond_equal) override; + Item* propagate_equal_fields(THD *, const Context &, COND_EQUAL *) override; + Item *replace_equal_field(THD *thd, uchar *arg) override; + uint32 max_display_length() const override + { return field->max_display_length(); } + Item_field *field_for_view_update() override { return this; } + int fix_outer_field(THD *thd, Field **field, Item **reference); + Item *update_value_transformer(THD *thd, uchar *select_arg) override; + Item *derived_field_transformer_for_having(THD *thd, uchar *arg) override; + Item *derived_field_transformer_for_where(THD *thd, uchar *arg) override; + Item *grouping_field_transformer_for_where(THD *thd, uchar *arg) override; + Item *in_subq_field_transformer_for_where(THD *thd, uchar *arg) override; + Item *in_subq_field_transformer_for_having(THD *thd, uchar *arg) override; + void print(String *str, enum_query_type query_type) override; + bool excl_dep_on_table(table_map tab_map) override; + bool excl_dep_on_grouping_fields(st_select_lex *sel) override; + bool excl_dep_on_in_subq_left_part(Item_in_subselect *subq_pred) override; + bool cleanup_excluding_fields_processor(void *arg) override + { return field ? 0 : cleanup_processor(arg); } + bool cleanup_excluding_const_fields_processor(void *arg) override + { return field && const_item() ? 0 : cleanup_processor(arg); } + + Item *get_copy(THD *thd) override + { return get_item_copy<Item_field>(thd, this); } + bool is_outer_field() const override + { + DBUG_ASSERT(fixed); + return field->table->pos_in_table_list->outer_join; + } + bool check_index_dependence(void *arg) override; + friend class Item_default_value; + friend class Item_insert_value; + friend class st_select_lex_unit; +}; + + +/** + Item_field for the ROW data type +*/ +class Item_field_row: public Item_field, + public Item_args +{ +public: + Item_field_row(THD *thd, Field *field) + :Item_field(thd, field), + Item_args() + { } + Item *get_copy(THD *thd) override + { return get_item_copy<Item_field_row>(thd, this); } + + const Type_handler *type_handler() const override + { return &type_handler_row; } + uint cols() const override { return arg_count; } + Item* element_index(uint i) override { return arg_count ? args[i] : this; } + Item** addr(uint i) override { return arg_count ? args + i : NULL; } + bool check_cols(uint c) override + { + if (cols() != c) + { + my_error(ER_OPERAND_COLUMNS, MYF(0), c); + return true; + } + return false; + } + bool row_create_items(THD *thd, List<Spvar_definition> *list); +}; + + +/* + @brief + Item_temptable_field is the same as Item_field, except that print() + continues to work even if the table has been dropped. + + @detail + + We need this item for "ANALYZE statement" feature. Query execution has + these steps: + + 1. Run the query. + 2. Cleanup starts. Temporary tables are destroyed + 3. print "ANALYZE statement" output, if needed + 4. Call close_thread_table() for regular tables. + + Step #4 is done after step #3, so "ANALYZE stmt" has no problem printing + Item_field objects that refer to regular tables. + + However, Step #3 is done after Step #2. Attempt to print Item_field objects + that refer to temporary tables will cause access to freed memory. + + To resolve this, we use Item_temptable_field to refer to items in temporary + (work) tables. +*/ + +class Item_temptable_field :public Item_field +{ +public: + Item_temptable_field(THD *thd, Name_resolution_context *context_arg, Field *field) + : Item_field(thd, context_arg, field) {} + + Item_temptable_field(THD *thd, Field *field) + : Item_field(thd, field) {} + + Item_temptable_field(THD *thd, Item_field *item) : Item_field(thd, item) {}; + + void print(String *str, enum_query_type query_type) override; +}; + + +class Item_null :public Item_basic_constant +{ +public: + Item_null(THD *thd, const char *name_par=0, CHARSET_INFO *cs= &my_charset_bin): + Item_basic_constant(thd) + { + maybe_null= null_value= TRUE; + max_length= 0; + name.str= name_par ? name_par : "NULL"; + name.length= strlen(name.str); + collation.set(cs, DERIVATION_IGNORABLE, MY_REPERTOIRE_ASCII); + } + Type type() const override { return NULL_ITEM; } + bool vcol_assignment_allowed_value() const override { return true; } + double val_real() override; + longlong val_int() override; + String *val_str(String *str) override; + my_decimal *val_decimal(my_decimal *) override; + bool get_date(THD *thd, MYSQL_TIME *ltime, date_mode_t fuzzydate) override; + longlong val_datetime_packed(THD *) override; + longlong val_time_packed(THD *) override; + int save_in_field(Field *field, bool no_conversions) override; + int save_safe_in_field(Field *field) override; + bool send(Protocol *protocol, st_value *buffer) override; + const Type_handler *type_handler() const override + { return &type_handler_null; } + bool basic_const_item() const override { return true; } + Item *clone_item(THD *thd) override; + bool const_is_null() const override { return true; } + bool is_null() override { return true; } + + void print(String *str, enum_query_type) override + { + str->append(STRING_WITH_LEN("NULL")); + } + + Item *safe_charset_converter(THD *thd, CHARSET_INFO *tocs) override; + bool check_partition_func_processor(void *) override { return false; } + Item_basic_constant *make_string_literal_concat(THD *thd, + const LEX_CSTRING *) + override; + Item *get_copy(THD *thd) override + { return get_item_copy<Item_null>(thd, this); } +}; + +class Item_null_result :public Item_null +{ +public: + Field *result_field; + Item_null_result(THD *thd): Item_null(thd), result_field(0) {} + bool is_result_field() override { return result_field != 0; } + const Type_handler *type_handler() const override + { + if (result_field) + return result_field->type_handler(); + return &type_handler_null; + } + Field *create_tmp_field_ex(MEM_ROOT *, TABLE *, Tmp_field_src *, + const Tmp_field_param *) override + { + DBUG_ASSERT(0); + return NULL; + } + void save_in_result_field(bool no_conversions) override + { + save_in_field(result_field, no_conversions); + } + bool check_partition_func_processor(void *) override { return true; } + bool check_vcol_func_processor(void *arg) override + { + return mark_unsupported_function(full_name(), arg, VCOL_IMPOSSIBLE); + } +}; + +/* + Item represents one placeholder ('?') of prepared statement + + Notes: + Item_param::field_type() is used when this item is in a temporary table. + This is NOT placeholder metadata sent to client, as this value + is assigned after sending metadata (in setup_one_conversion_function). + For example in case of 'SELECT ?' you'll get MYSQL_TYPE_STRING both + in result set and placeholders metadata, no matter what type you will + supply for this placeholder in mysql_stmt_execute. + + Item_param has two Type_handler pointers, + which can point to different handlers: + + 1. In the Type_handler_hybrid_field_type member + It's initialized in: + - Item_param::setup_conversion(), for client-server PS protocol, + according to the bind type. + - Item_param::set_from_item(), for EXECUTE and EXECUTE IMMEDIATE, + according to the actual parameter data type. + + 2. In the "value" member. + It's initialized in: + - Item_param::set_param_func(), for client-server PS protocol. + - Item_param::set_from_item(), for EXECUTE and EXECUTE IMMEDIATE. +*/ + +class Item_param :public Item_basic_value, + private Settable_routine_parameter, + public Rewritable_query_parameter, + private Type_handler_hybrid_field_type +{ + /* + NO_VALUE is a special value meaning that the parameter has not been + assigned yet. Item_param::state is assigned to NO_VALUE in constructor + and is used at prepare time. + + 1. At prepare time + Item_param::fix_fields() sets "fixed" to true, + but as Item_param::state is still NO_VALUE, + Item_param::basic_const_item() returns false. This prevents various + optimizations to happen at prepare time fix_fields(). + For example, in this query: + PREPARE stmt FROM 'SELECT FORMAT(10000,2,?)'; + Item_param::basic_const_item() is tested from + Item_func_format::fix_length_and_dec(). + + 2. At execute time: + When Item_param gets a value + (or a pseudo-value like DEFAULT_VALUE or IGNORE_VALUE): + - Item_param::state changes from NO_VALUE to something else + - Item_param::fixed is changed to true + All Item_param::set_xxx() make sure to do so. + In the state with an assigned value: + - Item_param::basic_const_item() returns true + - Item::type() returns NULL_ITEM or CONST_ITEM, + depending on the value assigned. + So in this state Item_param behaves in many cases like a literal. + + When Item_param::cleanup() is called: + - Item_param::state does not change + - Item_param::fixed changes to false + Note, this puts Item_param into an inconsistent state: + - Item_param::basic_const_item() still returns "true" + - Item_param::type() still pretends to be a basic constant Item + Both are not expected in combination with fixed==false. + However, these methods are not really called in this state, + see asserts in Item_param::basic_const_item() and Item_param::type(). + + When Item_param::reset() is called: + - Item_param::state changes to NO_VALUE + - Item_param::fixed changes to false + */ + enum enum_item_param_state + { + NO_VALUE, NULL_VALUE, SHORT_DATA_VALUE, LONG_DATA_VALUE, + DEFAULT_VALUE, IGNORE_VALUE + } state; + + void fix_temporal(uint32 max_length_arg, uint decimals_arg); + + struct CONVERSION_INFO + { + /* + Character sets conversion info for string values. + Character sets of client and connection defined at bind time are used + for all conversions, even if one of them is later changed (i.e. + between subsequent calls to mysql_stmt_execute). + */ + CHARSET_INFO *character_set_client; + CHARSET_INFO *character_set_of_placeholder; + /* + This points at character set of connection if conversion + to it is required (i. e. if placeholder typecode is not BLOB). + Otherwise it's equal to character_set_client (to simplify + check in convert_str_value()). + */ + CHARSET_INFO *final_character_set_of_str_value; + private: + bool needs_conversion() const + { + return final_character_set_of_str_value != + character_set_of_placeholder; + } + bool convert(THD *thd, String *str); + public: + void set(THD *thd, CHARSET_INFO *cs); + bool convert_if_needed(THD *thd, String *str) + { + /* + Check is so simple because all charsets were set up properly + in setup_one_conversion_function, where typecode of + placeholder was also taken into account: the variables are different + here only if conversion is really necessary. + */ + if (needs_conversion()) + return convert(thd, str); + str->set_charset(final_character_set_of_str_value); + return false; + } + }; + + bool m_empty_string_is_null; + + class PValue_simple + { + public: + union + { + longlong integer; + double real; + CONVERSION_INFO cs_info; + MYSQL_TIME time; + }; + void swap(PValue_simple &other) + { + swap_variables(PValue_simple, *this, other); + } + }; + + class PValue: public Type_handler_hybrid_field_type, + public PValue_simple, + public Value_source + { + public: + PValue(): Type_handler_hybrid_field_type(&type_handler_null) {} + my_decimal m_decimal; + String m_string; + /* + A buffer for string and long data values. Historically all allocated + values returned from val_str() were treated as eligible to + modification. I. e. in some cases Item_func_concat can append it's + second argument to return value of the first one. Because of that we + can't return the original buffer holding string data from val_str(), + and have to have one buffer for data and another just pointing to + the data. This is the latter one and it's returned from val_str(). + Can not be declared inside the union as it's not a POD type. + */ + String m_string_ptr; + + void swap(PValue &other) + { + Type_handler_hybrid_field_type::swap(other); + PValue_simple::swap(other); + m_decimal.swap(other.m_decimal); + m_string.swap(other.m_string); + m_string_ptr.swap(other.m_string_ptr); + } + double val_real(const Type_std_attributes *attr) const; + longlong val_int(const Type_std_attributes *attr) const; + my_decimal *val_decimal(my_decimal *dec, const Type_std_attributes *attr); + String *val_str(String *str, const Type_std_attributes *attr); + }; + + PValue value; + + const String *value_query_val_str(THD *thd, String* str) const; + Item *value_clone_item(THD *thd); + bool is_evaluable_expression() const override; + bool can_return_value() const; + +public: + /* + Used for bulk protocol only. + */ + enum enum_indicator_type indicator; + + const Type_handler *type_handler() const override + { return Type_handler_hybrid_field_type::type_handler(); } + + bool vcol_assignment_allowed_value() const override + { + switch (state) { + case NULL_VALUE: + case DEFAULT_VALUE: + case IGNORE_VALUE: + return true; + case NO_VALUE: + case SHORT_DATA_VALUE: + case LONG_DATA_VALUE: + break; + } + return false; + } + + Item_param(THD *thd, const LEX_CSTRING *name_arg, + uint pos_in_query_arg, uint len_in_query_arg); + + Type type() const override + { + // Don't pretend to be a constant unless value for this item is set. + switch (state) { + case NO_VALUE: return PARAM_ITEM; + case NULL_VALUE: return NULL_ITEM; + case SHORT_DATA_VALUE: return CONST_ITEM; + case LONG_DATA_VALUE: return CONST_ITEM; + case DEFAULT_VALUE: return PARAM_ITEM; + case IGNORE_VALUE: return PARAM_ITEM; + } + DBUG_ASSERT(0); + return PARAM_ITEM; + } + + bool is_order_clause_position() const override + { + return state == SHORT_DATA_VALUE && + type_handler()->is_order_clause_position_type(); + } + + const Item_const *get_item_const() const override + { + switch (state) { + case SHORT_DATA_VALUE: + case LONG_DATA_VALUE: + case NULL_VALUE: + return this; + case IGNORE_VALUE: + case DEFAULT_VALUE: + case NO_VALUE: + break; + } + return NULL; + } + + bool const_is_null() const override { return state == NULL_VALUE; } + bool can_return_const_value(Item_result type) const + { + return can_return_value() && + value.type_handler()->cmp_type() == type && + type_handler()->cmp_type() == type; + } + const longlong *const_ptr_longlong() const override + { return can_return_const_value(INT_RESULT) ? &value.integer : NULL; } + const double *const_ptr_double() const override + { return can_return_const_value(REAL_RESULT) ? &value.real : NULL; } + const my_decimal *const_ptr_my_decimal() const override + { return can_return_const_value(DECIMAL_RESULT) ? &value.m_decimal : NULL; } + const MYSQL_TIME *const_ptr_mysql_time() const override + { return can_return_const_value(TIME_RESULT) ? &value.time : NULL; } + const String *const_ptr_string() const override + { return can_return_const_value(STRING_RESULT) ? &value.m_string : NULL; } + + double val_real() override + { + return can_return_value() ? value.val_real(this) : 0e0; + } + longlong val_int() override + { + return can_return_value() ? value.val_int(this) : 0; + } + my_decimal *val_decimal(my_decimal *dec) override + { + return can_return_value() ? value.val_decimal(dec, this) : NULL; + } + String *val_str(String *str) override + { + return can_return_value() ? value.val_str(str, this) : NULL; + } + bool get_date(THD *thd, MYSQL_TIME *tm, date_mode_t fuzzydate) override; + bool val_native(THD *thd, Native *to) override + { + return Item_param::type_handler()->Item_param_val_native(thd, this, to); + } + + int save_in_field(Field *field, bool no_conversions) override; + + void set_default(); + void set_ignore(); + void set_null(); + void set_int(longlong i, uint32 max_length_arg); + void set_double(double i); + void set_decimal(const char *str, ulong length); + void set_decimal(const my_decimal *dv, bool unsigned_arg); + bool set_str(const char *str, ulong length, + CHARSET_INFO *fromcs, CHARSET_INFO *tocs); + bool set_longdata(const char *str, ulong length); + void set_time(MYSQL_TIME *tm, timestamp_type type, uint32 max_length_arg); + void set_time(const MYSQL_TIME *tm, uint32 max_length_arg, uint decimals_arg); + bool set_from_item(THD *thd, Item *item); + void reset(); + + void set_param_tiny(uchar **pos, ulong len); + void set_param_short(uchar **pos, ulong len); + void set_param_int32(uchar **pos, ulong len); + void set_param_int64(uchar **pos, ulong len); + void set_param_float(uchar **pos, ulong len); + void set_param_double(uchar **pos, ulong len); + void set_param_decimal(uchar **pos, ulong len); + void set_param_time(uchar **pos, ulong len); + void set_param_datetime(uchar **pos, ulong len); + void set_param_date(uchar **pos, ulong len); + void set_param_str(uchar **pos, ulong len); + + void setup_conversion(THD *thd, uchar param_type); + void setup_conversion_blob(THD *thd); + void setup_conversion_string(THD *thd, CHARSET_INFO *fromcs); + + /* + Assign placeholder value from bind data. + Note, that 'len' has different semantics in embedded library (as we + don't need to check that packet is not broken there). See + sql_prepare.cc for details. + */ + void set_param_func(uchar **pos, ulong len) + { + /* + To avoid Item_param::set_xxx() asserting on data type mismatch, + we set the value type handler here: + - It can not be initialized yet after Item_param::setup_conversion(). + - Also, for LIMIT clause parameters, the value type handler might have + changed from the real type handler to type_handler_longlong. + So here we'll restore it. + */ + const Type_handler *h= Item_param::type_handler(); + value.set_handler(h); + h->Item_param_set_param_func(this, pos, len); + } + + bool set_value(THD *thd, const Type_all_attributes *attr, + const st_value *val, const Type_handler *h) + { + value.set_handler(h); // See comments in set_param_func() + return h->Item_param_set_from_value(thd, this, attr, val); + } + + bool set_limit_clause_param(longlong nr) + { + value.set_handler(&type_handler_slonglong); + set_int(nr, MY_INT64_NUM_DECIMAL_DIGITS); + return !unsigned_flag && value.integer < 0; + } + const String *query_val_str(THD *thd, String *str) const; + + bool convert_str_value(THD *thd); + + /* + If value for parameter was not set we treat it as non-const + so no one will use parameters value in fix_fields still + parameter is constant during execution. + */ + bool const_item() const override + { + return state != NO_VALUE; + } + table_map used_tables() const override + { + return state != NO_VALUE ? (table_map)0 : PARAM_TABLE_BIT; + } + void print(String *str, enum_query_type query_type) override; + bool is_null() override + { DBUG_ASSERT(state != NO_VALUE); return state == NULL_VALUE; } + bool basic_const_item() const override; + bool has_no_value() const + { + return state == NO_VALUE; + } + bool has_long_data_value() const + { + return state == LONG_DATA_VALUE; + } + bool has_int_value() const + { + return state == SHORT_DATA_VALUE && + value.type_handler()->cmp_type() == INT_RESULT; + } + /* + This method is used to make a copy of a basic constant item when + propagating constants in the optimizer. The reason to create a new + item and not use the existing one is not precisely known (2005/04/16). + Probably we are trying to preserve tree structure of items, in other + words, avoid pointing at one item from two different nodes of the tree. + Return a new basic constant item if parameter value is a basic + constant, assert otherwise. This method is called only if + basic_const_item returned TRUE. + */ + Item *safe_charset_converter(THD *thd, CHARSET_INFO *tocs) override; + Item *clone_item(THD *thd) override; + void set_param_type_and_swap_value(Item_param *from); + + Rewritable_query_parameter *get_rewritable_query_parameter() override + { return this; } + Settable_routine_parameter *get_settable_routine_parameter() override + { return m_is_settable_routine_parameter ? this : nullptr; } + + bool append_for_log(THD *thd, String *str) override; + bool check_vcol_func_processor(void *) override { return false; } + Item *get_copy(THD *) override { return nullptr; } + + bool add_as_clone(THD *thd); + void sync_clones(); + bool register_clone(Item_param *i) { return m_clones.push_back(i); } + +private: + void invalid_default_param() const; + + bool set_value(THD *thd, sp_rcontext *ctx, Item **it) override; + + void set_out_param_info(Send_field *info) override; + +public: + const Send_field *get_out_param_info() const override; + + Item_param *get_item_param() override { return this; } + + void make_send_field(THD *thd, Send_field *field) override; + +private: + Send_field *m_out_param_info; + bool m_is_settable_routine_parameter; + /* + Array of all references of this parameter marker used in a CTE to its clones + created for copies of this marker used the CTE's copies. It's used to + synchronize the actual value of the parameter with the values of the clones. + */ + Mem_root_array<Item_param *, true> m_clones; +}; + + +class Item_int :public Item_num +{ +public: + longlong value; + Item_int(THD *thd, int32 i,size_t length= MY_INT32_NUM_DECIMAL_DIGITS): + Item_num(thd), value((longlong) i) + { max_length=(uint32)length; } + Item_int(THD *thd, longlong i,size_t length= MY_INT64_NUM_DECIMAL_DIGITS): + Item_num(thd), value(i) + { max_length=(uint32)length; } + Item_int(THD *thd, ulonglong i, size_t length= MY_INT64_NUM_DECIMAL_DIGITS): + Item_num(thd), value((longlong)i) + { max_length=(uint32)length; unsigned_flag= 1; } + Item_int(THD *thd, const char *str_arg,longlong i,size_t length): + Item_num(thd), value(i) + { + max_length=(uint32)length; + name.str= str_arg; name.length= safe_strlen(name.str); + } + Item_int(THD *thd, const char *str_arg,longlong i,size_t length, bool flag): + Item_num(thd), value(i) + { + max_length=(uint32)length; + name.str= str_arg; name.length= safe_strlen(name.str); + unsigned_flag= flag; + } + Item_int(THD *thd, const char *str_arg, size_t length=64); + const Type_handler *type_handler() const override + { return type_handler_long_or_longlong(); } + Field *create_field_for_create_select(MEM_ROOT *root, TABLE *table) override + { return tmp_table_field_from_field_type(root, table); } + const longlong *const_ptr_longlong() const override { return &value; } + longlong val_int() override { return value; } + longlong val_int_min() const override { return value; } + double val_real() override { return (double) value; } + my_decimal *val_decimal(my_decimal *) override; + String *val_str(String*) override; + int save_in_field(Field *field, bool no_conversions) override; + bool is_order_clause_position() const override { return true; } + Item *clone_item(THD *thd) override; + void print(String *str, enum_query_type query_type) override; + Item *neg(THD *thd) override; + uint decimal_precision() const override + { return (uint) (max_length - MY_TEST(value < 0)); } + Item *get_copy(THD *thd) override + { return get_item_copy<Item_int>(thd, this); } +}; + + +/* + We sometimes need to distinguish a number from a boolean: + a[1] and a[true] are different things in XPath. + Also in JSON boolean values should be treated differently. +*/ +class Item_bool :public Item_int +{ +public: + Item_bool(THD *thd, const char *str_arg, longlong i): + Item_int(thd, str_arg, i, 1) {} + Item_bool(THD *thd, bool i) :Item_int(thd, (longlong) i, 1) { } + bool is_bool_literal() const override { return true; } + Item *neg_transformer(THD *thd) override; + const Type_handler *type_handler() const override + { return &type_handler_bool; } + const Type_handler *fixed_type_handler() const override + { return &type_handler_bool; } + void quick_fix_field() override + { + /* + We can get here when Item_bool is created instead of a constant + predicate at various condition optimization stages in sql_select. + */ + } +}; + + +class Item_uint :public Item_int +{ +public: + Item_uint(THD *thd, const char *str_arg, size_t length); + Item_uint(THD *thd, ulonglong i): Item_int(thd, i, 10) {} + Item_uint(THD *thd, const char *str_arg, longlong i, uint length); + double val_real() { return ulonglong2double((ulonglong)value); } + Item *clone_item(THD *thd); + Item *neg(THD *thd); + uint decimal_precision() const { return max_length; } + Item *get_copy(THD *thd) + { return get_item_copy<Item_uint>(thd, this); } +}; + + +class Item_datetime :public Item_int +{ +protected: + MYSQL_TIME ltime; +public: + Item_datetime(THD *thd): Item_int(thd, 0) { unsigned_flag=0; } + int save_in_field(Field *field, bool no_conversions) override; + longlong val_int() override; + double val_real() override { return (double)val_int(); } + void set(longlong packed, enum_mysql_timestamp_type ts_type); + bool get_date(THD *thd, MYSQL_TIME *to, date_mode_t fuzzydate) override + { + *to= ltime; + return false; + } +}; + + +/* decimal (fixed point) constant */ +class Item_decimal :public Item_num +{ +protected: + my_decimal decimal_value; +public: + Item_decimal(THD *thd, const char *str_arg, size_t length, + CHARSET_INFO *charset); + Item_decimal(THD *thd, const char *str, const my_decimal *val_arg, + uint decimal_par, uint length); + Item_decimal(THD *thd, const my_decimal *value_par); + Item_decimal(THD *thd, longlong val, bool unsig); + Item_decimal(THD *thd, double val, int precision, int scale); + Item_decimal(THD *thd, const uchar *bin, int precision, int scale); + + const Type_handler *type_handler() const override + { return &type_handler_newdecimal; } + longlong val_int() override + { return decimal_value.to_longlong(unsigned_flag); } + double val_real() override { return decimal_value.to_double(); } + String *val_str(String *to) override { return decimal_value.to_string(to); } + my_decimal *val_decimal(my_decimal *val) override { return &decimal_value; } + const my_decimal *const_ptr_my_decimal() const override + { return &decimal_value; } + int save_in_field(Field *field, bool no_conversions) override; + Item *clone_item(THD *thd) override; + void print(String *str, enum_query_type query_type) override + { + decimal_value.to_string(&str_value); + str->append(str_value); + } + Item *neg(THD *thd) override; + uint decimal_precision() const override { return decimal_value.precision(); } + void set_decimal_value(my_decimal *value_par); + Item *get_copy(THD *thd) override + { return get_item_copy<Item_decimal>(thd, this); } +}; + + +class Item_float :public Item_num +{ + const char *presentation; +public: + double value; + Item_float(THD *thd, const char *str_arg, size_t length); + Item_float(THD *thd, const char *str, double val_arg, uint decimal_par, + uint length): Item_num(thd), value(val_arg) + { + presentation= name.str= str; + name.length= safe_strlen(str); + decimals=(uint8) decimal_par; + max_length= length; + } + Item_float(THD *thd, double value_par, uint decimal_par): + Item_num(thd), presentation(0), value(value_par) + { + decimals= (uint8) decimal_par; + } + int save_in_field(Field *field, bool no_conversions) override; + const Type_handler *type_handler() const override + { return &type_handler_double; } + const double *const_ptr_double() const override { return &value; } + double val_real() override { return value; } + longlong val_int() override + { + if (value <= (double) LONGLONG_MIN) + { + return LONGLONG_MIN; + } + else if (value >= (double) (ulonglong) LONGLONG_MAX) + { + return LONGLONG_MAX; + } + return (longlong) rint(value); + } + String *val_str(String*) override; + my_decimal *val_decimal(my_decimal *) override; + Item *clone_item(THD *thd) override; + Item *neg(THD *thd) override; + void print(String *str, enum_query_type query_type) override; + Item *get_copy(THD *thd) override + { return get_item_copy<Item_float>(thd, this); } +}; + + +class Item_static_float_func :public Item_float +{ + const char *func_name; +public: + Item_static_float_func(THD *thd, const char *str, double val_arg, + uint decimal_par, uint length): + Item_float(thd, NullS, val_arg, decimal_par, length), func_name(str) + {} + + void print(String *str, enum_query_type) override + { + str->append(func_name); + } + + Item *safe_charset_converter(THD *thd, CHARSET_INFO *tocs) override + { + return const_charset_converter(thd, tocs, true, func_name); + } +}; + + +class Item_string :public Item_literal +{ +protected: + void fix_from_value(Derivation dv, const Metadata metadata) + { + fix_charset_and_length(str_value.charset(), dv, metadata); + } + void fix_and_set_name_from_value(THD *thd, Derivation dv, + const Metadata metadata) + { + fix_from_value(dv, metadata); + set_name(thd, &str_value); + } +protected: + /* Just create an item and do not fill string representation */ + Item_string(THD *thd, CHARSET_INFO *cs, Derivation dv= DERIVATION_COERCIBLE): + Item_literal(thd) + { + collation.set(cs, dv); + max_length= 0; + set_name(thd, NULL, 0, system_charset_info); + decimals= NOT_FIXED_DEC; + } +public: + Item_string(THD *thd, CHARSET_INFO *csi, const char *str_arg, uint length_arg) + :Item_literal(thd) + { + collation.set(csi, DERIVATION_COERCIBLE); + set_name(thd, NULL, 0, system_charset_info); + decimals= NOT_FIXED_DEC; + str_value.copy(str_arg, length_arg, csi); + max_length= str_value.numchars() * csi->mbmaxlen; + } + // Constructors with the item name set from its value + Item_string(THD *thd, const char *str, uint length, CHARSET_INFO *cs, + Derivation dv, my_repertoire_t repertoire) + :Item_literal(thd) + { + str_value.set_or_copy_aligned(str, length, cs); + fix_and_set_name_from_value(thd, dv, Metadata(&str_value, repertoire)); + } + Item_string(THD *thd, const char *str, size_t length, + CHARSET_INFO *cs, Derivation dv= DERIVATION_COERCIBLE) + :Item_literal(thd) + { + str_value.set_or_copy_aligned(str, length, cs); + fix_and_set_name_from_value(thd, dv, Metadata(&str_value)); + } + Item_string(THD *thd, const String *str, CHARSET_INFO *tocs, uint *conv_errors, + Derivation dv, my_repertoire_t repertoire) + :Item_literal(thd) + { + if (str_value.copy(str, tocs, conv_errors)) + str_value.set("", 0, tocs); // EOM ? + str_value.mark_as_const(); + fix_and_set_name_from_value(thd, dv, Metadata(&str_value, repertoire)); + } + // Constructors with an externally provided item name + Item_string(THD *thd, const LEX_CSTRING &name_par, const LEX_CSTRING &str, + CHARSET_INFO *cs, Derivation dv= DERIVATION_COERCIBLE) + :Item_literal(thd) + { + str_value.set_or_copy_aligned(str.str, str.length, cs); + fix_from_value(dv, Metadata(&str_value)); + set_name(thd, name_par); + } + Item_string(THD *thd, const LEX_CSTRING &name_par, const LEX_CSTRING &str, + CHARSET_INFO *cs, Derivation dv, my_repertoire_t repertoire) + :Item_literal(thd) + { + str_value.set_or_copy_aligned(str.str, str.length, cs); + fix_from_value(dv, Metadata(&str_value, repertoire)); + set_name(thd, name_par); + } + void print_value(String *to) const + { + str_value.print(to); + } + double val_real() override; + longlong val_int() override; + const String *const_ptr_string() const override { return &str_value; } + String *val_str(String*) override + { + return (String*) &str_value; + } + my_decimal *val_decimal(my_decimal *) override; + bool get_date(THD *thd, MYSQL_TIME *ltime, date_mode_t fuzzydate) override + { + return get_date_from_string(thd, ltime, fuzzydate); + } + int save_in_field(Field *field, bool no_conversions) override; + const Type_handler *type_handler() const override + { return &type_handler_varchar; } + Item *clone_item(THD *thd) override; + Item *safe_charset_converter(THD *thd, CHARSET_INFO *tocs) override + { + return const_charset_converter(thd, tocs, true); + } + inline void append(const char *str, uint length) + { + str_value.append(str, length); + max_length= str_value.numchars() * collation.collation->mbmaxlen; + } + void print(String *str, enum_query_type query_type) override; + + /** + Return TRUE if character-set-introducer was explicitly specified in the + original query for this item (text literal). + + This operation is to be called from Item_string::print(). The idea is + that when a query is generated (re-constructed) from the Item-tree, + character-set-introducers should appear only for those literals, where + they were explicitly specified by the user. Otherwise, that may lead to + loss collation information (character set introducers implies default + collation for the literal). + + Basically, that makes sense only for views and hopefully will be gone + one day when we start using original query as a view definition. + + @return This operation returns the value of m_cs_specified attribute. + @retval TRUE if character set introducer was explicitly specified in + the original query. + @retval FALSE otherwise. + */ + virtual bool is_cs_specified() const + { + return false; + } + + String *check_well_formed_result(bool send_error) + { return Item::check_well_formed_result(&str_value, send_error); } + + Item_basic_constant *make_string_literal_concat(THD *thd, + const LEX_CSTRING *) + override; + Item *make_odbc_literal(THD *thd, const LEX_CSTRING *typestr) override; + + Item *get_copy(THD *thd) override + { return get_item_copy<Item_string>(thd, this); } + +}; + + +class Item_string_with_introducer :public Item_string +{ +public: + Item_string_with_introducer(THD *thd, const LEX_CSTRING &str, + CHARSET_INFO *cs): + Item_string(thd, str.str, str.length, cs) + { } + Item_string_with_introducer(THD *thd, const LEX_CSTRING &name_arg, + const LEX_CSTRING &str, CHARSET_INFO *tocs): + Item_string(thd, name_arg, str, tocs) + { } + virtual bool is_cs_specified() const + { + return true; + } +}; + + +class Item_string_sys :public Item_string +{ +public: + Item_string_sys(THD *thd, const char *str, uint length): + Item_string(thd, str, length, system_charset_info) + { } + Item_string_sys(THD *thd, const char *str): + Item_string(thd, str, (uint) strlen(str), system_charset_info) + { } +}; + + +class Item_string_ascii :public Item_string +{ +public: + Item_string_ascii(THD *thd, const char *str, uint length): + Item_string(thd, str, length, &my_charset_latin1, + DERIVATION_COERCIBLE, MY_REPERTOIRE_ASCII) + { } + Item_string_ascii(THD *thd, const char *str): + Item_string(thd, str, (uint) strlen(str), &my_charset_latin1, + DERIVATION_COERCIBLE, MY_REPERTOIRE_ASCII) + { } +}; + + +class Item_static_string_func :public Item_string +{ + const LEX_CSTRING func_name; +public: + Item_static_string_func(THD *thd, const LEX_CSTRING &name_par, + const LEX_CSTRING &str, CHARSET_INFO *cs, + Derivation dv= DERIVATION_COERCIBLE): + Item_string(thd, LEX_CSTRING({NullS,0}), str, cs, dv), func_name(name_par) + {} + Item_static_string_func(THD *thd, const LEX_CSTRING &name_par, + const String *str, + CHARSET_INFO *tocs, uint *conv_errors, + Derivation dv, my_repertoire_t repertoire): + Item_string(thd, str, tocs, conv_errors, dv, repertoire), + func_name(name_par) + {} + Item *safe_charset_converter(THD *thd, CHARSET_INFO *tocs) override + { + return const_charset_converter(thd, tocs, true, func_name.str); + } + + void print(String *str, enum_query_type) override + { + str->append(func_name); + } + + bool check_partition_func_processor(void *) override { return true; } + + bool check_vcol_func_processor(void *arg) override + { // VCOL_TIME_FUNC because the value is not constant, but does not + // require fix_fields() to be re-run for every statement. + return mark_unsupported_function(func_name.str, arg, VCOL_TIME_FUNC); + } +}; + + +/* for show tables */ +class Item_partition_func_safe_string: public Item_string +{ +public: + Item_partition_func_safe_string(THD *thd, const LEX_CSTRING &name_arg, + uint length, CHARSET_INFO *cs): + Item_string(thd, name_arg, LEX_CSTRING({0,0}), cs) + { + max_length= length; + } + bool check_vcol_func_processor(void *arg) + { + return mark_unsupported_function("safe_string", arg, VCOL_IMPOSSIBLE); + } +}; + + +/** + Item_empty_string -- is a utility class to put an item into List<Item> + which is then used in protocol.send_result_set_metadata() when sending SHOW output to + the client. +*/ + +class Item_empty_string :public Item_partition_func_safe_string +{ +public: + Item_empty_string(THD *thd, const LEX_CSTRING &header, uint length, + CHARSET_INFO *cs= &my_charset_utf8mb3_general_ci) + :Item_partition_func_safe_string(thd, header, length * cs->mbmaxlen, cs) + { } + Item_empty_string(THD *thd, const char *header, uint length, + CHARSET_INFO *cs= &my_charset_utf8mb3_general_ci) + :Item_partition_func_safe_string(thd, LEX_CSTRING({header, strlen(header)}), + length * cs->mbmaxlen, cs) + { } + void make_send_field(THD *thd, Send_field *field); +}; + + +class Item_return_int :public Item_int +{ + enum_field_types int_field_type; +public: + Item_return_int(THD *thd, const char *name_arg, uint length, + enum_field_types field_type_arg, longlong value_arg= 0): + Item_int(thd, name_arg, value_arg, length), int_field_type(field_type_arg) + { + unsigned_flag=1; + } + const Type_handler *type_handler() const + { + const Type_handler *h= + Type_handler::get_handler_by_field_type(int_field_type); + return unsigned_flag ? h->type_handler_unsigned() : h; + } +}; + + +/** + Item_hex_constant -- a common class for hex literals: X'HHHH' and 0xHHHH +*/ +class Item_hex_constant: public Item_literal +{ +private: + void hex_string_init(THD *thd, const char *str, size_t str_length); +public: + Item_hex_constant(THD *thd): Item_literal(thd) + { + hex_string_init(thd, "", 0); + } + Item_hex_constant(THD *thd, const char *str, size_t str_length): + Item_literal(thd) + { + hex_string_init(thd, str, str_length); + } + const Type_handler *type_handler() const { return &type_handler_varchar; } + virtual Item *safe_charset_converter(THD *thd, CHARSET_INFO *tocs) + { + return const_charset_converter(thd, tocs, true); + } + const String *const_ptr_string() const { return &str_value; } + String *val_str(String*) { return &str_value; } + bool get_date(THD *thd, MYSQL_TIME *ltime, date_mode_t fuzzydate) + { + return type_handler()->Item_get_date_with_warn(thd, this, ltime, fuzzydate); + } +}; + + +/** + Item_hex_hybrid -- is a class implementing 0xHHHH literals, e.g.: + SELECT 0x3132; + They can behave as numbers and as strings depending on context. +*/ +class Item_hex_hybrid: public Item_hex_constant +{ +public: + Item_hex_hybrid(THD *thd): Item_hex_constant(thd) {} + Item_hex_hybrid(THD *thd, const char *str, size_t str_length): + Item_hex_constant(thd, str, str_length) {} + const Type_handler *type_handler() const override + { return &type_handler_hex_hybrid; } + uint decimal_precision() const override; + double val_real() override + { + return (double) (ulonglong) Item_hex_hybrid::val_int(); + } + longlong val_int() override + { + return longlong_from_hex_hybrid(str_value.ptr(), str_value.length()); + } + my_decimal *val_decimal(my_decimal *decimal_value) override + { + longlong value= Item_hex_hybrid::val_int(); + int2my_decimal(E_DEC_FATAL_ERROR, value, TRUE, decimal_value); + return decimal_value; + } + int save_in_field(Field *field, bool) override + { + field->set_notnull(); + return field->store_hex_hybrid(str_value.ptr(), str_value.length()); + } + void print(String *str, enum_query_type query_type) override; + Item *get_copy(THD *thd) override + { return get_item_copy<Item_hex_hybrid>(thd, this); } +}; + + +/** + Item_hex_string -- is a class implementing X'HHHH' literals, e.g.: + SELECT X'3132'; + Unlike Item_hex_hybrid, X'HHHH' literals behave as strings in all contexts. + X'HHHH' are also used in replication of string constants in case of + "dangerous" charsets (sjis, cp932, big5, gbk) who can have backslash (0x5C) + as the second byte of a multi-byte character, so using '\' escaping for + these charsets is not desirable. +*/ +class Item_hex_string: public Item_hex_constant +{ +public: + Item_hex_string(THD *thd): Item_hex_constant(thd) {} + Item_hex_string(THD *thd, const char *str, size_t str_length): + Item_hex_constant(thd, str, str_length) {} + longlong val_int() override + { + return longlong_from_string_with_check(&str_value); + } + double val_real() override + { + return double_from_string_with_check(&str_value); + } + my_decimal *val_decimal(my_decimal *decimal_value) override + { + return val_decimal_from_string(decimal_value); + } + int save_in_field(Field *field, bool) override + { + field->set_notnull(); + return field->store(str_value.ptr(), str_value.length(), + collation.collation); + } + void print(String *str, enum_query_type query_type) override; + Item *get_copy(THD *thd) override + { return get_item_copy<Item_hex_string>(thd, this); } +}; + + +class Item_bin_string: public Item_hex_hybrid +{ +public: + Item_bin_string(THD *thd, const char *str, size_t str_length); +}; + + +class Item_timestamp_literal: public Item_literal +{ + Timestamp_or_zero_datetime m_value; +public: + Item_timestamp_literal(THD *thd) + :Item_literal(thd) + { } + const Type_handler *type_handler() const override + { return &type_handler_timestamp2; } + int save_in_field(Field *field, bool) override + { + Timestamp_or_zero_datetime_native native(m_value, decimals); + return native.save_in_field(field, decimals); + } + longlong val_int() override + { + return m_value.to_datetime(current_thd).to_longlong(); + } + double val_real() override + { + return m_value.to_datetime(current_thd).to_double(); + } + String *val_str(String *to) override + { + return m_value.to_datetime(current_thd).to_string(to, decimals); + } + my_decimal *val_decimal(my_decimal *to) override + { + return m_value.to_datetime(current_thd).to_decimal(to); + } + bool get_date(THD *thd, MYSQL_TIME *ltime, date_mode_t fuzzydate) override + { + bool res= m_value.to_TIME(thd, ltime, fuzzydate); + DBUG_ASSERT(!res); + return res; + } + bool val_native(THD *thd, Native *to) override + { + return m_value.to_native(to, decimals); + } + void set_value(const Timestamp_or_zero_datetime &value) + { + m_value= value; + } + Item *get_copy(THD *thd) override + { return get_item_copy<Item_timestamp_literal>(thd, this); } +}; + + +class Item_temporal_literal :public Item_literal +{ +public: + Item_temporal_literal(THD *thd) + :Item_literal(thd) + { + collation= DTCollation_numeric(); + decimals= 0; + } + Item_temporal_literal(THD *thd, uint dec_arg): + Item_literal(thd) + { + collation= DTCollation_numeric(); + decimals= dec_arg; + } + + int save_in_field(Field *field, bool no_conversions) override + { return save_date_in_field(field, no_conversions); } +}; + + +/** + DATE'2010-01-01' +*/ +class Item_date_literal: public Item_temporal_literal +{ +protected: + Date cached_time; + bool update_null() + { + return maybe_null && + (null_value= cached_time.check_date_with_warn(current_thd)); + } +public: + Item_date_literal(THD *thd, const Date *ltime) + :Item_temporal_literal(thd), + cached_time(*ltime) + { + DBUG_ASSERT(cached_time.is_valid_date()); + max_length= MAX_DATE_WIDTH; + /* + If date has zero month or day, it can return NULL in case of + NO_ZERO_DATE or NO_ZERO_IN_DATE. + If date is `February 30`, it can return NULL in case if + no ALLOW_INVALID_DATES is set. + We can't set null_value using the current sql_mode here in constructor, + because sql_mode can change in case of prepared statements + between PREPARE and EXECUTE. + Here we only set maybe_null to true if the value has such anomalies. + Later (during execution time), if maybe_null is true, then the value + will be checked per row, according to the execution time sql_mode. + The check_date() below call should cover all cases mentioned. + */ + maybe_null= cached_time.check_date(TIME_NO_ZERO_DATE | TIME_NO_ZERO_IN_DATE); + } + const Type_handler *type_handler() const override + { return &type_handler_newdate; } + void print(String *str, enum_query_type query_type) override; + const MYSQL_TIME *const_ptr_mysql_time() const override + { + return cached_time.get_mysql_time(); + } + Item *clone_item(THD *thd) override; + longlong val_int() override + { + return update_null() ? 0 : cached_time.to_longlong(); + } + double val_real() override + { + return update_null() ? 0 : cached_time.to_double(); + } + String *val_str(String *to) override + { + return update_null() ? 0 : cached_time.to_string(to); + } + my_decimal *val_decimal(my_decimal *to) override + { + return update_null() ? 0 : cached_time.to_decimal(to); + } + longlong val_datetime_packed(THD *thd) override + { + return update_null() ? 0 : cached_time.valid_date_to_packed(); + } + bool get_date(THD *thd, MYSQL_TIME *res, date_mode_t fuzzydate) override; + Item *get_copy(THD *thd) override + { return get_item_copy<Item_date_literal>(thd, this); } +}; + + +/** + TIME'10:10:10' +*/ +class Item_time_literal: public Item_temporal_literal +{ +protected: + Time cached_time; +public: + Item_time_literal(THD *thd, const Time *ltime, uint dec_arg): + Item_temporal_literal(thd, dec_arg), + cached_time(*ltime) + { + DBUG_ASSERT(cached_time.is_valid_time()); + max_length= MIN_TIME_WIDTH + (decimals ? decimals + 1 : 0); + } + const Type_handler *type_handler() const override + { return &type_handler_time2; } + void print(String *str, enum_query_type query_type) override; + const MYSQL_TIME *const_ptr_mysql_time() const override + { + return cached_time.get_mysql_time(); + } + Item *clone_item(THD *thd) override; + longlong val_int() override { return cached_time.to_longlong(); } + double val_real() override { return cached_time.to_double(); } + String *val_str(String *to) override + { return cached_time.to_string(to, decimals); } + my_decimal *val_decimal(my_decimal *to) override + { return cached_time.to_decimal(to); } + longlong val_time_packed(THD *thd) override + { + return cached_time.valid_time_to_packed(); + } + bool get_date(THD *thd, MYSQL_TIME *res, date_mode_t fuzzydate) override; + bool val_native(THD *thd, Native *to) override + { + return Time(thd, this).to_native(to, decimals); + } + Item *get_copy(THD *thd) override + { return get_item_copy<Item_time_literal>(thd, this); } +}; + + +/** + TIMESTAMP'2001-01-01 10:20:30' +*/ +class Item_datetime_literal: public Item_temporal_literal +{ +protected: + Datetime cached_time; + bool update_null() + { + return maybe_null && + (null_value= cached_time.check_date_with_warn(current_thd)); + } +public: + Item_datetime_literal(THD *thd, const Datetime *ltime, uint dec_arg): + Item_temporal_literal(thd, dec_arg), + cached_time(*ltime) + { + DBUG_ASSERT(cached_time.is_valid_datetime()); + max_length= MAX_DATETIME_WIDTH + (decimals ? decimals + 1 : 0); + // See the comment on maybe_null in Item_date_literal + maybe_null= cached_time.check_date(TIME_NO_ZERO_DATE | TIME_NO_ZERO_IN_DATE); + } + const Type_handler *type_handler() const override + { return &type_handler_datetime2; } + void print(String *str, enum_query_type query_type) override; + const MYSQL_TIME *const_ptr_mysql_time() const override + { + return cached_time.get_mysql_time(); + } + Item *clone_item(THD *thd) override; + longlong val_int() override + { + return update_null() ? 0 : cached_time.to_longlong(); + } + double val_real() override + { + return update_null() ? 0 : cached_time.to_double(); + } + String *val_str(String *to) override + { + return update_null() ? NULL : cached_time.to_string(to, decimals); + } + my_decimal *val_decimal(my_decimal *to) override + { + return update_null() ? NULL : cached_time.to_decimal(to); + } + longlong val_datetime_packed(THD *thd) override + { + return update_null() ? 0 : cached_time.valid_datetime_to_packed(); + } + bool get_date(THD *thd, MYSQL_TIME *res, date_mode_t fuzzydate) override; + Item *get_copy(THD *thd) override + { return get_item_copy<Item_datetime_literal>(thd, this); } +}; + + +/** + An error-safe counterpart for Item_date_literal +*/ +class Item_date_literal_for_invalid_dates: public Item_date_literal +{ + /** + During equal field propagation we can replace non-temporal constants + found in equalities to their native temporal equivalents: + WHERE date_column='2001-01-01' ... -> + WHERE date_column=DATE'2001-01-01' ... + + This is done to make the eqial field propagation code handle mixtures of + different temporal types in the same expressions easier (MDEV-8706), e.g. + WHERE LENGTH(date_column)=10 AND date_column=TIME'00:00:00' + + Item_date_literal_for_invalid_dates::get_date() + (unlike the regular Item_date_literal::get_date()) + does not check the result for NO_ZERO_IN_DATE and NO_ZERO_DATE, + always returns success (false), and does not produce error/warning messages. + + We need these _for_invalid_dates classes to be able to rewrite: + SELECT * FROM t1 WHERE date_column='0000-00-00' ... + to: + SELECT * FROM t1 WHERE date_column=DATE'0000-00-00' ... + + to avoid returning NULL value instead of '0000-00-00' even + in sql_mode=TRADITIONAL. + */ +public: + Item_date_literal_for_invalid_dates(THD *thd, const Date *ltime) + :Item_date_literal(thd, ltime) + { + maybe_null= false; + } + bool get_date(THD *thd, MYSQL_TIME *ltime, date_mode_t fuzzydate) + { + cached_time.copy_to_mysql_time(ltime); + return (null_value= false); + } +}; + + +/** + An error-safe counterpart for Item_datetime_literal + (see Item_date_literal_for_invalid_dates for comments) +*/ +class Item_datetime_literal_for_invalid_dates: public Item_datetime_literal +{ +public: + Item_datetime_literal_for_invalid_dates(THD *thd, + const Datetime *ltime, uint dec_arg) + :Item_datetime_literal(thd, ltime, dec_arg) + { + maybe_null= false; + } + bool get_date(THD *thd, MYSQL_TIME *ltime, date_mode_t fuzzydate) + { + cached_time.copy_to_mysql_time(ltime); + return (null_value= false); + } +}; + + +class Used_tables_and_const_cache +{ +public: + /* + In some cases used_tables_cache is not what used_tables() return + so the method should be used where one need used tables bit map + (even internally in Item_func_* code). + */ + table_map used_tables_cache; + bool const_item_cache; + + Used_tables_and_const_cache() + :used_tables_cache(0), + const_item_cache(true) + { } + Used_tables_and_const_cache(const Used_tables_and_const_cache *other) + :used_tables_cache(other->used_tables_cache), + const_item_cache(other->const_item_cache) + { } + void used_tables_and_const_cache_init() + { + used_tables_cache= 0; + const_item_cache= true; + } + void used_tables_and_const_cache_join(const Item *item) + { + used_tables_cache|= item->used_tables(); + const_item_cache&= item->const_item(); + } + void used_tables_and_const_cache_update_and_join(Item *item) + { + item->update_used_tables(); + used_tables_and_const_cache_join(item); + } + /* + Call update_used_tables() for all "argc" items in the array "argv" + and join with the current cache. + "this" must be initialized with a constructor or + re-initialized with used_tables_and_const_cache_init(). + */ + void used_tables_and_const_cache_update_and_join(uint argc, Item **argv) + { + for (uint i=0 ; i < argc ; i++) + used_tables_and_const_cache_update_and_join(argv[i]); + } + /* + Call update_used_tables() for all items in the list + and join with the current cache. + "this" must be initialized with a constructor or + re-initialized with used_tables_and_const_cache_init(). + */ + void used_tables_and_const_cache_update_and_join(List<Item> &list) + { + List_iterator_fast<Item> li(list); + Item *item; + while ((item=li++)) + used_tables_and_const_cache_update_and_join(item); + } +}; + + +/** + An abstract class representing common features of + regular functions and aggregate functions. +*/ +class Item_func_or_sum: public Item_result_field, + public Item_args, + public Used_tables_and_const_cache, + public With_subquery_cache +{ +protected: + bool agg_arg_charsets(DTCollation &c, Item **items, uint nitems, + uint flags, int item_sep) + { + return Type_std_attributes::agg_arg_charsets(c, func_name(), + items, nitems, + flags, item_sep); + } + bool agg_arg_charsets_for_string_result(DTCollation &c, + Item **items, uint nitems, + int item_sep= 1) + { + return Type_std_attributes:: + agg_arg_charsets_for_string_result(c, func_name(), + items, nitems, item_sep); + } + bool agg_arg_charsets_for_string_result_with_comparison(DTCollation &c, + Item **items, + uint nitems, + int item_sep= 1) + { + return Type_std_attributes:: + agg_arg_charsets_for_string_result_with_comparison(c, func_name(), + items, nitems, + item_sep); + } + + /* + Aggregate arguments for comparison, e.g: a=b, a LIKE b, a RLIKE b + - don't convert to @@character_set_connection if all arguments are numbers + - don't allow DERIVATION_NONE + */ + bool agg_arg_charsets_for_comparison(DTCollation &c, + Item **items, uint nitems, + int item_sep= 1) + { + return Type_std_attributes:: + agg_arg_charsets_for_comparison(c, func_name(), items, nitems, item_sep); + } + +public: + // This method is used by Arg_comparator + bool agg_arg_charsets_for_comparison(CHARSET_INFO **cs, Item **a, Item **b) + { + DTCollation tmp; + if (tmp.set((*a)->collation, (*b)->collation, MY_COLL_CMP_CONV) || + tmp.derivation == DERIVATION_NONE) + { + my_error(ER_CANT_AGGREGATE_2COLLATIONS,MYF(0), + (*a)->collation.collation->name, + (*a)->collation.derivation_name(), + (*b)->collation.collation->name, + (*b)->collation.derivation_name(), + func_name()); + return true; + } + if (agg_item_set_converter(tmp, func_name(), + a, 1, MY_COLL_CMP_CONV, 1) || + agg_item_set_converter(tmp, func_name(), + b, 1, MY_COLL_CMP_CONV, 1)) + return true; + *cs= tmp.collation; + return false; + } + +public: + Item_func_or_sum(THD *thd): Item_result_field(thd), Item_args() {} + Item_func_or_sum(THD *thd, Item *a): Item_result_field(thd), Item_args(a) { } + Item_func_or_sum(THD *thd, Item *a, Item *b): + Item_result_field(thd), Item_args(a, b) { } + Item_func_or_sum(THD *thd, Item *a, Item *b, Item *c): + Item_result_field(thd), Item_args(thd, a, b, c) { } + Item_func_or_sum(THD *thd, Item *a, Item *b, Item *c, Item *d): + Item_result_field(thd), Item_args(thd, a, b, c, d) { } + Item_func_or_sum(THD *thd, Item *a, Item *b, Item *c, Item *d, Item *e): + Item_result_field(thd), Item_args(thd, a, b, c, d, e) { } + Item_func_or_sum(THD *thd, Item_func_or_sum *item): + Item_result_field(thd, item), Item_args(thd, item), + Used_tables_and_const_cache(item) { } + Item_func_or_sum(THD *thd, List<Item> &list): + Item_result_field(thd), Item_args(thd, list) { } + bool with_subquery() const override + { DBUG_ASSERT(fixed); return m_with_subquery; } + bool walk(Item_processor processor, bool walk_subquery, void *arg) override + { + if (walk_args(processor, walk_subquery, arg)) + return true; + return (this->*processor)(arg); + } + /* + This method is used for debug purposes to print the name of an + item to the debug log. The second use of this method is as + a helper function of print() and error messages, where it is + applicable. To suit both goals it should return a meaningful, + distinguishable and sintactically correct string. This method + should not be used for runtime type identification, use enum + {Sum}Functype and Item_func::functype()/Item_sum::sum_func() + instead. + Added here, to the parent class of both Item_func and Item_sum. + + NOTE: for Items inherited from Item_sum, func_name() return part of + function name till first argument (including '(') to make difference in + names for functions with 'distinct' clause and without 'distinct' and + also to make printing of items inherited from Item_sum uniform. + */ + virtual const char *func_name() const= 0; + virtual bool fix_length_and_dec()= 0; + bool const_item() const override { return const_item_cache; } + table_map used_tables() const override { return used_tables_cache; } + Item* build_clone(THD *thd) override; + Sql_mode_dependency value_depends_on_sql_mode() const override + { + return Item_args::value_depends_on_sql_mode_bit_or().soft_to_hard(); + } +}; + +class sp_head; +class sp_name; +struct st_sp_security_context; + +class Item_sp +{ +protected: + // Can be NULL in some non-SELECT queries + Name_resolution_context *context; +public: + sp_name *m_name; + sp_head *m_sp; + TABLE *dummy_table; + uchar result_buf[64]; + sp_rcontext *func_ctx; + MEM_ROOT sp_mem_root; + Query_arena *sp_query_arena; + + /* + The result field of the stored function. + */ + Field *sp_result_field; + Item_sp(THD *thd, Name_resolution_context *context_arg, sp_name *name_arg); + Item_sp(THD *thd, Item_sp *item); + const char *func_name(THD *thd) const; + void cleanup(); + bool sp_check_access(THD *thd); + bool execute(THD *thd, bool *null_value, Item **args, uint arg_count); + bool execute_impl(THD *thd, Item **args, uint arg_count); + bool init_result_field(THD *thd, uint max_length, uint maybe_null, + bool *null_value, LEX_CSTRING *name); + void process_error(THD *thd) + { + if (context) + context->process_error(thd); + } +}; + +class Item_ref :public Item_ident, + protected With_sum_func_cache +{ +protected: + void set_properties(); + bool set_properties_only; // the item doesn't need full fix_fields +public: + enum Ref_Type { REF, DIRECT_REF, VIEW_REF, OUTER_REF, AGGREGATE_REF }; + Item **ref; + bool reference_trough_name; + Item_ref(THD *thd, Name_resolution_context *context_arg, + const LEX_CSTRING &db_arg, const LEX_CSTRING &table_name_arg, + const LEX_CSTRING &field_name_arg): + Item_ident(thd, context_arg, db_arg, table_name_arg, field_name_arg), + set_properties_only(0), ref(0), reference_trough_name(1) {} + Item_ref(THD *thd, Name_resolution_context *context_arg, + const LEX_CSTRING &field_name_arg) + :Item_ref(thd, context_arg, null_clex_str, null_clex_str, field_name_arg) + { } + /* + This constructor is used in two scenarios: + A) *item = NULL + No initialization is performed, fix_fields() call will be necessary. + + B) *item points to an Item this Item_ref will refer to. This is + used for GROUP BY. fix_fields() will not be called in this case, + so we call set_properties to make this item "fixed". set_properties + performs a subset of action Item_ref::fix_fields does, and this subset + is enough for Item_ref's used in GROUP BY. + + TODO we probably fix a superset of problems like in BUG#6658. Check this + with Bar, and if we have a more broader set of problems like this. + */ + Item_ref(THD *thd, Name_resolution_context *context_arg, Item **item, + const LEX_CSTRING &table_name_arg, const LEX_CSTRING &field_name_arg, + bool alias_name_used_arg= FALSE); + Item_ref(THD *thd, TABLE_LIST *view_arg, Item **item, + const LEX_CSTRING &field_name_arg, bool alias_name_used_arg= FALSE); + + /* Constructor need to process subselect with temporary tables (see Item) */ + Item_ref(THD *thd, Item_ref *item) + :Item_ident(thd, item), With_sum_func_cache(*item), + set_properties_only(0), ref(item->ref) {} + Type type() const override { return REF_ITEM; } + Type real_type() const override + { return ref ? (*ref)->type() : REF_ITEM; } + bool eq(const Item *item, bool binary_cmp) const override + { + Item *it= ((Item *) item)->real_item(); + return ref && (*ref)->eq(it, binary_cmp); + } + void save_val(Field *to) override; + void save_result(Field *to) override; + double val_real() override; + longlong val_int() override; + my_decimal *val_decimal(my_decimal *) override; + bool val_bool() override; + String *val_str(String* tmp) override; + bool val_native(THD *thd, Native *to) override; + bool is_null() override; + bool get_date(THD *thd, MYSQL_TIME *ltime, date_mode_t fuzzydate) override; + longlong val_datetime_packed(THD *) override; + longlong val_time_packed(THD *) override; + double val_result() override; + longlong val_int_result() override; + String *str_result(String* tmp) override; + bool val_native_result(THD *thd, Native *to) override; + my_decimal *val_decimal_result(my_decimal *) override; + bool val_bool_result() override; + bool is_null_result() override; + bool send(Protocol *prot, st_value *buffer) override; + void make_send_field(THD *thd, Send_field *field) override; + bool fix_fields(THD *, Item **) override; + void fix_after_pullout(st_select_lex *new_parent, Item **ref, bool merge) + override; + int save_in_field(Field *field, bool no_conversions) override; + void save_org_in_field(Field *field, fast_field_copier optimizer_data) + override; + fast_field_copier setup_fast_field_copier(Field *field) override + { return (*ref)->setup_fast_field_copier(field); } + const Type_handler *type_handler() const override + { return (*ref)->type_handler(); } + const Type_handler *real_type_handler() const override + { return (*ref)->real_type_handler(); } + Field *get_tmp_table_field() override + { return result_field ? result_field : (*ref)->get_tmp_table_field(); } + Item *get_tmp_table_item(THD *thd) override; + Field *create_tmp_field_ex(MEM_ROOT *root, TABLE *table, Tmp_field_src *src, + const Tmp_field_param *param) override; + Item* propagate_equal_fields(THD *, const Context &, COND_EQUAL *) override; + table_map used_tables() const override; + void update_used_tables() override; + COND *build_equal_items(THD *thd, COND_EQUAL *inherited, + bool link_item_fields, + COND_EQUAL **cond_equal_ref) override + { + /* + normilize_cond() replaced all conditions of type + WHERE/HAVING field + to: + WHERE/HAVING field<>0 + By the time of a build_equal_items() call, all such conditions should + already be replaced. No Item_ref referencing to Item_field are possible. + */ + DBUG_ASSERT(real_type() != FIELD_ITEM); + return Item_ident::build_equal_items(thd, inherited, link_item_fields, + cond_equal_ref); + } + bool const_item() const override { return (*ref)->const_item(); } + table_map not_null_tables() const override + { + return depended_from ? 0 : (*ref)->not_null_tables(); + } + bool find_not_null_fields(table_map allowed) override + { + return depended_from ? false : (*ref)->find_not_null_fields(allowed); + } + void save_in_result_field(bool no_conversions) override + { + (*ref)->save_in_field(result_field, no_conversions); + } + Item *real_item() override { return ref ? (*ref)->real_item() : this; } + const TYPELIB *get_typelib() const override + { + return ref ? (*ref)->get_typelib() : NULL; + } + bool is_json_type() override { return (*ref)->is_json_type(); } + + bool walk(Item_processor processor, bool walk_subquery, void *arg) override + { + if (ref && *ref) + return (*ref)->walk(processor, walk_subquery, arg) || + (this->*processor)(arg); + else + return FALSE; + } + Item* transform(THD *thd, Item_transformer, uchar *arg) override; + Item* compile(THD *thd, Item_analyzer analyzer, uchar **arg_p, + Item_transformer transformer, uchar *arg_t) override; + bool enumerate_field_refs_processor(void *arg) override + { return (*ref)->enumerate_field_refs_processor(arg); } + void no_rows_in_result() override + { + (*ref)->no_rows_in_result(); + } + void restore_to_before_no_rows_in_result() override + { + (*ref)->restore_to_before_no_rows_in_result(); + } + void print(String *str, enum_query_type query_type) override; + enum precedence precedence() const override + { + return ref ? (*ref)->precedence() : DEFAULT_PRECEDENCE; + } + void cleanup() override; + Item_field *field_for_view_update() override + { return (*ref)->field_for_view_update(); } + Load_data_outvar *get_load_data_outvar() override + { + return (*ref)->get_load_data_outvar(); + } + virtual Ref_Type ref_type() { return REF; } + + // Row emulation: forwarding of ROW-related calls to ref + uint cols() const override + { + return ref && result_type() == ROW_RESULT ? (*ref)->cols() : 1; + } + Item* element_index(uint i) override + { + return ref && result_type() == ROW_RESULT ? (*ref)->element_index(i) : this; + } + Item** addr(uint i) override + { + return ref && result_type() == ROW_RESULT ? (*ref)->addr(i) : 0; + } + bool check_cols(uint c) override + { + return ref && result_type() == ROW_RESULT ? (*ref)->check_cols(c) + : Item::check_cols(c); + } + bool null_inside() override + { + return ref && result_type() == ROW_RESULT ? (*ref)->null_inside() : 0; + } + void bring_value() override + { + if (ref && result_type() == ROW_RESULT) + (*ref)->bring_value(); + } + bool check_vcol_func_processor(void *arg) override + { + return mark_unsupported_function("ref", arg, VCOL_IMPOSSIBLE); + } + bool basic_const_item() const override + { return ref && (*ref)->basic_const_item(); } + bool is_outer_field() const override + { + DBUG_ASSERT(fixed); + DBUG_ASSERT(ref); + return (*ref)->is_outer_field(); + } + + Item* build_clone(THD *thd) override; + + /** + Checks if the item tree that ref points to contains a subquery. + */ + bool with_subquery() const override { return (*ref)->with_subquery(); } + Item *get_copy(THD *thd) override + { return get_item_copy<Item_ref>(thd, this); } + bool excl_dep_on_table(table_map tab_map) override + { + table_map used= used_tables(); + if (used & OUTER_REF_TABLE_BIT) + return false; + return (used == tab_map) || (*ref)->excl_dep_on_table(tab_map); + } + bool excl_dep_on_grouping_fields(st_select_lex *sel) override + { return (*ref)->excl_dep_on_grouping_fields(sel); } + bool excl_dep_on_in_subq_left_part(Item_in_subselect *subq_pred) override + { return (*ref)->excl_dep_on_in_subq_left_part(subq_pred); } + bool cleanup_excluding_fields_processor(void *arg) override + { + Item *item= real_item(); + if (item && item->type() == FIELD_ITEM && + ((Item_field *)item)->field) + return 0; + return cleanup_processor(arg); + } + bool cleanup_excluding_const_fields_processor(void *arg) override + { + Item *item= real_item(); + if (item && item->type() == FIELD_ITEM && + ((Item_field *) item)->field && item->const_item()) + return 0; + return cleanup_processor(arg); + } + bool with_sum_func() const override { return m_with_sum_func; } + With_sum_func_cache* get_with_sum_func_cache() override { return this; } + Item *field_transformer_for_having_pushdown(THD *thd, uchar *arg) override + { return (*ref)->field_transformer_for_having_pushdown(thd, arg); } + Item *remove_item_direct_ref() override + { + *ref= (*ref)->remove_item_direct_ref(); + return this; + } +}; + + +/* + The same as Item_ref, but get value from val_* family of method to get + value of item on which it referred instead of result* family. +*/ +class Item_direct_ref :public Item_ref +{ +public: + Item_direct_ref(THD *thd, Name_resolution_context *context_arg, Item **item, + const LEX_CSTRING &table_name_arg, + const LEX_CSTRING &field_name_arg, + bool alias_name_used_arg= FALSE): + Item_ref(thd, context_arg, item, table_name_arg, + field_name_arg, alias_name_used_arg) + {} + /* Constructor need to process subselect with temporary tables (see Item) */ + Item_direct_ref(THD *thd, Item_direct_ref *item) : Item_ref(thd, item) {} + Item_direct_ref(THD *thd, TABLE_LIST *view_arg, Item **item, + const LEX_CSTRING &field_name_arg, + bool alias_name_used_arg= FALSE): + Item_ref(thd, view_arg, item, field_name_arg, + alias_name_used_arg) + {} + + bool fix_fields(THD *thd, Item **it) override + { + if ((*ref)->fix_fields_if_needed_for_scalar(thd, ref)) + return TRUE; + return Item_ref::fix_fields(thd, it); + } + void save_val(Field *to) override; + /* Below we should have all val() methods as in Item_ref */ + double val_real() override; + longlong val_int() override; + my_decimal *val_decimal(my_decimal *) override; + bool val_bool() override; + String *val_str(String* tmp) override; + bool val_native(THD *thd, Native *to) override; + bool is_null() override; + bool get_date(THD *thd, MYSQL_TIME *ltime, date_mode_t fuzzydate) override; + longlong val_datetime_packed(THD *) override; + longlong val_time_packed(THD *) override; + Ref_Type ref_type() override { return DIRECT_REF; } + Item *get_copy(THD *thd) override + { return get_item_copy<Item_direct_ref>(thd, this); } + Item *remove_item_direct_ref() override + { return (*ref)->remove_item_direct_ref(); } +}; + + +/** + This class is the same as Item_direct_ref but created to wrap Item_ident + before fix_fields() call +*/ + +class Item_direct_ref_to_ident :public Item_direct_ref +{ + Item_ident *ident; +public: + Item_direct_ref_to_ident(THD *thd, Item_ident *item): + Item_direct_ref(thd, item->context, (Item**)&item, item->table_name, + item->field_name, FALSE) + { + ident= item; + ref= (Item**)&ident; + } + + bool fix_fields(THD *thd, Item **it) override + { + DBUG_ASSERT(ident->type() == FIELD_ITEM || ident->type() == REF_ITEM); + if (ident->fix_fields_if_needed_for_scalar(thd, ref)) + return TRUE; + set_properties(); + return FALSE; + } + + void print(String *str, enum_query_type query_type) override + { ident->print(str, query_type); } + +}; + + +class Item_cache; +class Expression_cache; +class Expression_cache_tracker; + +/** + The objects of this class can store its values in an expression cache. +*/ + +class Item_cache_wrapper :public Item_result_field, + public With_subquery_cache, + protected With_sum_func_cache +{ +private: + /* Pointer on the cached expression */ + Item *orig_item; + Expression_cache *expr_cache; + /* + In order to put the expression into the expression cache and return + value of val_*() method, we will need to get the expression value twice + (probably in different types). In order to avoid making two + (potentially costly) orig_item->val_*() calls, we store expression value + in this Item_cache object. + */ + Item_cache *expr_value; + + List<Item> parameters; + + Item *check_cache(); + void cache(); + void init_on_demand(); + +public: + Item_cache_wrapper(THD *thd, Item *item_arg); + ~Item_cache_wrapper(); + + Type type() const override { return EXPR_CACHE_ITEM; } + Type real_type() const override { return orig_item->type(); } + bool with_subquery() const override + { DBUG_ASSERT(fixed); return m_with_subquery; } + bool with_sum_func() const override { return m_with_sum_func; } + With_sum_func_cache* get_with_sum_func_cache() override { return this; } + + bool set_cache(THD *thd); + Expression_cache_tracker* init_tracker(MEM_ROOT *mem_root); + + bool fix_fields(THD *thd, Item **it) override; + void cleanup() override; + + Item *get_orig_item() const { return orig_item; } + + /* Methods of getting value which should be cached in the cache */ + void save_val(Field *to) override; + double val_real() override; + longlong val_int() override; + String *val_str(String* tmp) override; + bool val_native(THD *thd, Native *to) override; + my_decimal *val_decimal(my_decimal *) override; + bool val_bool() override; + bool is_null() override; + bool get_date(THD *thd, MYSQL_TIME *ltime, date_mode_t fuzzydate) override; + bool send(Protocol *protocol, st_value *buffer) override; + void save_org_in_field(Field *field, fast_field_copier) override + { + save_val(field); + } + void save_in_result_field(bool) override { save_val(result_field); } + Item* get_tmp_table_item(THD *thd_arg) override; + + /* Following methods make this item transparent as much as possible */ + + void print(String *str, enum_query_type query_type) override; + const char *full_name() const override { return orig_item->full_name(); } + void make_send_field(THD *thd, Send_field *field) override + { orig_item->make_send_field(thd, field); } + bool eq(const Item *item, bool binary_cmp) const override + { + Item *it= const_cast<Item*>(item)->real_item(); + return orig_item->eq(it, binary_cmp); + } + void fix_after_pullout(st_select_lex *new_parent, Item **refptr, bool merge) + override + { + orig_item->fix_after_pullout(new_parent, &orig_item, merge); + } + int save_in_field(Field *to, bool no_conversions) override; + const Type_handler *type_handler() const override + { return orig_item->type_handler(); } + table_map used_tables() const override { return orig_item->used_tables(); } + void update_used_tables() override { orig_item->update_used_tables(); } + bool const_item() const override { return orig_item->const_item(); } + table_map not_null_tables() const override + { return orig_item->not_null_tables(); } + bool walk(Item_processor processor, bool walk_subquery, void *arg) override + { + return orig_item->walk(processor, walk_subquery, arg) || + (this->*processor)(arg); + } + bool enumerate_field_refs_processor(void *arg) override + { return orig_item->enumerate_field_refs_processor(arg); } + Item_field *field_for_view_update() override + { return orig_item->field_for_view_update(); } + + /* Row emulation: forwarding of ROW-related calls to orig_item */ + uint cols() const override + { return result_type() == ROW_RESULT ? orig_item->cols() : 1; } + Item* element_index(uint i) override + { return result_type() == ROW_RESULT ? orig_item->element_index(i) : this; } + Item** addr(uint i) override + { return result_type() == ROW_RESULT ? orig_item->addr(i) : 0; } + bool check_cols(uint c) override + { + return (result_type() == ROW_RESULT ? + orig_item->check_cols(c) : + Item::check_cols(c)); + } + bool null_inside() override + { return result_type() == ROW_RESULT ? orig_item->null_inside() : 0; } + void bring_value() override + { + if (result_type() == ROW_RESULT) + orig_item->bring_value(); + } + bool is_expensive() override { return orig_item->is_expensive(); } + bool is_expensive_processor(void *arg) override + { return orig_item->is_expensive_processor(arg); } + bool check_vcol_func_processor(void *arg) override + { + return mark_unsupported_function("cache", arg, VCOL_IMPOSSIBLE); + } + Item *get_copy(THD *thd) override + { return get_item_copy<Item_cache_wrapper>(thd, this); } + Item *build_clone(THD *) override { return nullptr; } +}; + + +/* + Class for view fields, the same as Item_direct_ref, but call fix_fields + of reference if it is not called yet +*/ +class Item_direct_view_ref :public Item_direct_ref +{ + Item_equal *item_equal; + TABLE_LIST *view; + TABLE *null_ref_table; + +#define NO_NULL_TABLE (reinterpret_cast<TABLE *>(0x1)) + + void set_null_ref_table() + { + if (!view->is_inner_table_of_outer_join() || + !(null_ref_table= view->get_real_join_table())) + null_ref_table= NO_NULL_TABLE; + } + + bool check_null_ref() + { + DBUG_ASSERT(null_ref_table); + if (null_ref_table != NO_NULL_TABLE && null_ref_table->null_row) + { + null_value= 1; + return TRUE; + } + return FALSE; + } + +public: + Item_direct_view_ref(THD *thd, Name_resolution_context *context_arg, + Item **item, + LEX_CSTRING &table_name_arg, + LEX_CSTRING &field_name_arg, + TABLE_LIST *view_arg): + Item_direct_ref(thd, context_arg, item, table_name_arg, field_name_arg), + item_equal(0), view(view_arg), + null_ref_table(NULL) + { + if (fixed) + set_null_ref_table(); + } + + bool fix_fields(THD *, Item **) override; + bool eq(const Item *item, bool binary_cmp) const override; + Item *get_tmp_table_item(THD *thd) override + { + if (const_item()) + return copy_or_same(thd); + Item *item= Item_ref::get_tmp_table_item(thd); + item->name= name; + return item; + } + Ref_Type ref_type() override { return VIEW_REF; } + Item_equal *get_item_equal() override { return item_equal; } + void set_item_equal(Item_equal *item_eq) override { item_equal= item_eq; } + Item_equal *find_item_equal(COND_EQUAL *cond_equal) override; + Item* propagate_equal_fields(THD *, const Context &, COND_EQUAL *) override; + Item *replace_equal_field(THD *thd, uchar *arg) override; + table_map used_tables() const override; + void update_used_tables() override; + table_map not_null_tables() const override; + bool const_item() const override + { + return (*ref)->const_item() && (null_ref_table == NO_NULL_TABLE); + } + TABLE *get_null_ref_table() const { return null_ref_table; } + bool walk(Item_processor processor, bool walk_subquery, void *arg) override + { + return (*ref)->walk(processor, walk_subquery, arg) || + (this->*processor)(arg); + } + bool view_used_tables_processor(void *arg) override + { + TABLE_LIST *view_arg= (TABLE_LIST *) arg; + if (view_arg == view) + view_arg->view_used_tables|= (*ref)->used_tables(); + return 0; + } + bool excl_dep_on_table(table_map tab_map) override; + bool excl_dep_on_grouping_fields(st_select_lex *sel) override; + bool excl_dep_on_in_subq_left_part(Item_in_subselect *subq_pred) override; + Item *derived_field_transformer_for_having(THD *thd, uchar *arg) override; + Item *derived_field_transformer_for_where(THD *thd, uchar *arg) override; + Item *grouping_field_transformer_for_where(THD *thd, uchar *arg) override; + Item *in_subq_field_transformer_for_where(THD *thd, uchar *arg) override; + Item *in_subq_field_transformer_for_having(THD *thd, uchar *arg) override; + + void save_val(Field *to) override + { + if (check_null_ref()) + to->set_null(); + else + Item_direct_ref::save_val(to); + } + double val_real() override + { + if (check_null_ref()) + return 0; + else + return Item_direct_ref::val_real(); + } + longlong val_int() override + { + if (check_null_ref()) + return 0; + else + return Item_direct_ref::val_int(); + } + String *val_str(String* tmp) override + { + if (check_null_ref()) + return NULL; + else + return Item_direct_ref::val_str(tmp); + } + bool val_native(THD *thd, Native *to) override + { + if (check_null_ref()) + return true; + return Item_direct_ref::val_native(thd, to); + } + my_decimal *val_decimal(my_decimal *tmp) override + { + if (check_null_ref()) + return NULL; + else + return Item_direct_ref::val_decimal(tmp); + } + bool val_bool() override + { + if (check_null_ref()) + return 0; + else + return Item_direct_ref::val_bool(); + } + bool is_null() override + { + if (check_null_ref()) + return 1; + else + return Item_direct_ref::is_null(); + } + bool get_date(THD *thd, MYSQL_TIME *ltime, date_mode_t fuzzydate) override + { + if (check_null_ref()) + { + bzero((char*) ltime,sizeof(*ltime)); + return 1; + } + return Item_direct_ref::get_date(thd, ltime, fuzzydate); + } + longlong val_time_packed(THD *thd) override + { + if (check_null_ref()) + return 0; + else + return Item_direct_ref::val_time_packed(thd); + } + longlong val_datetime_packed(THD *thd) override + { + if (check_null_ref()) + return 0; + else + return Item_direct_ref::val_datetime_packed(thd); + } + bool send(Protocol *protocol, st_value *buffer) override; + void save_org_in_field(Field *field, fast_field_copier) override + { + if (check_null_ref()) + field->set_null(); + else + Item_direct_ref::save_val(field); + } + void save_in_result_field(bool no_conversions) override + { + if (check_null_ref()) + result_field->set_null(); + else + Item_direct_ref::save_in_result_field(no_conversions); + } + + void cleanup() override + { + null_ref_table= NULL; + item_equal= NULL; + Item_direct_ref::cleanup(); + } + /* + TODO move these val_*_result function to Item_direct_ref (maybe) + */ + double val_result() override; + longlong val_int_result() override; + String *str_result(String* tmp) override; + my_decimal *val_decimal_result(my_decimal *val) override; + bool val_bool_result() override; + + Item *get_copy(THD *thd) override + { return get_item_copy<Item_direct_view_ref>(thd, this); } + Item *field_transformer_for_having_pushdown(THD *, uchar *) override + { return this; } + Item *remove_item_direct_ref() override { return this; } +}; + + +/* + Class for outer fields. + An object of this class is created when the select where the outer field was + resolved is a grouping one. After it has been fixed the ref field will point + to either an Item_ref or an Item_direct_ref object which will be used to + access the field. + See also comments for the fix_inner_refs() and the + Item_field::fix_outer_field() functions. +*/ + +class Item_sum; +class Item_outer_ref :public Item_direct_ref +{ +public: + Item *outer_ref; + /* The aggregate function under which this outer ref is used, if any. */ + Item_sum *in_sum_func; + /* + TRUE <=> that the outer_ref is already present in the select list + of the outer select. + */ + bool found_in_select_list; + bool found_in_group_by; + Item_outer_ref(THD *thd, Name_resolution_context *context_arg, + Item_field *outer_field_arg): + Item_direct_ref(thd, context_arg, 0, outer_field_arg->table_name, + outer_field_arg->field_name), + outer_ref(outer_field_arg), in_sum_func(0), + found_in_select_list(0), found_in_group_by(0) + { + ref= &outer_ref; + set_properties(); + fixed= 0; /* reset flag set in set_properties() */ + } + Item_outer_ref(THD *thd, Name_resolution_context *context_arg, Item **item, + const LEX_CSTRING &table_name_arg, LEX_CSTRING &field_name_arg, + bool alias_name_used_arg): + Item_direct_ref(thd, context_arg, item, table_name_arg, field_name_arg, + alias_name_used_arg), + outer_ref(0), in_sum_func(0), found_in_select_list(1), found_in_group_by(0) + {} + void save_in_result_field(bool no_conversions) override + { + outer_ref->save_org_in_field(result_field, NULL); + } + bool fix_fields(THD *, Item **) override; + void fix_after_pullout(st_select_lex *new_parent, Item **ref, bool merge) + override; + table_map used_tables() const override + { + return (*ref)->const_item() ? 0 : OUTER_REF_TABLE_BIT; + } + table_map not_null_tables() const override { return 0; } + Ref_Type ref_type() override { return OUTER_REF; } + bool check_inner_refs_processor(void * arg) override; +}; + + +class Item_in_subselect; + + +/* + An object of this class: + - Converts val_XXX() calls to ref->val_XXX_result() calls, like Item_ref. + - Sets owner->was_null=TRUE if it has returned a NULL value from any + val_XXX() function. This allows to inject an Item_ref_null_helper + object into subquery and then check if the subquery has produced a row + with NULL value. +*/ + +class Item_ref_null_helper: public Item_ref +{ +protected: + Item_in_subselect* owner; +public: + Item_ref_null_helper(THD *thd, Name_resolution_context *context_arg, + Item_in_subselect* master, Item **item, + const LEX_CSTRING &table_name_arg, + const LEX_CSTRING &field_name_arg): + Item_ref(thd, context_arg, item, table_name_arg, field_name_arg), + owner(master) {} + void save_val(Field *to) override; + double val_real() override; + longlong val_int() override; + String* val_str(String* s) override; + my_decimal *val_decimal(my_decimal *) override; + bool val_bool() override; + bool get_date(THD *thd, MYSQL_TIME *ltime, date_mode_t fuzzydate) override; + bool val_native(THD *thd, Native *to) override; + void print(String *str, enum_query_type query_type) override; + table_map used_tables() const override; + Item *get_copy(THD *thd) override + { return get_item_copy<Item_ref_null_helper>(thd, this); } +}; + +/* + The following class is used to optimize comparing of date and bigint columns + We need to save the original item ('ref') to be able to call + ref->save_in_field(). This is used to create index search keys. + + An instance of Item_int_with_ref may have signed or unsigned integer value. + +*/ + +class Item_int_with_ref :public Item_int +{ + Item *ref; +public: + Item_int_with_ref(THD *thd, longlong i, Item *ref_arg, bool unsigned_arg): + Item_int(thd, i), ref(ref_arg) + { + unsigned_flag= unsigned_arg; + } + int save_in_field(Field *field, bool no_conversions) override + { + return ref->save_in_field(field, no_conversions); + } + Item *clone_item(THD *thd) override; + Item *real_item() override { return ref; } +}; + +#ifdef MYSQL_SERVER +#include "item_sum.h" +#include "item_func.h" +#include "item_row.h" +#include "item_cmpfunc.h" +#include "item_strfunc.h" +#include "item_timefunc.h" +#include "item_subselect.h" +#include "item_xmlfunc.h" +#include "item_jsonfunc.h" +#include "item_create.h" +#include "item_vers.h" +#endif + +/** + Base class to implement typed value caching Item classes + + Item_copy_ classes are very similar to the corresponding Item_ + classes (e.g. Item_copy_string is similar to Item_string) but they add + the following additional functionality to Item_ : + 1. Nullability + 2. Possibility to store the value not only on instantiation time, + but also later. + Item_copy_ classes are a functionality subset of Item_cache_ + classes, as e.g. they don't support comparisons with the original Item + as Item_cache_ classes do. + Item_copy_ classes are used in GROUP BY calculation. + TODO: Item_copy should be made an abstract interface and Item_copy_ + classes should inherit both the respective Item_ class and the interface. + Ideally we should drop Item_copy_ classes altogether and merge + their functionality to Item_cache_ (and these should be made to inherit + from Item_). +*/ + +class Item_copy :public Item, + public Type_handler_hybrid_field_type +{ +protected: + + /** + Type_handler_hybrid_field_type is used to + store the type of the resulting field that would be used to store the data + in the cache. This is to avoid calls to the original item. + */ + + /** The original item that is copied */ + Item *item; + + /** + Constructor of the Item_copy class + + stores metadata information about the original class as well as a + pointer to it. + */ + Item_copy(THD *thd, Item *i): Item(thd) + { + DBUG_ASSERT(i->is_fixed()); + item= i; + null_value=maybe_null=item->maybe_null; + Type_std_attributes::set(item); + name= item->name; + set_handler(item->type_handler()); + } + +public: + + /** + Update the cache with the value of the original item + + This is the method that updates the cached value. + It must be explicitly called by the user of this class to store the value + of the original item in the cache. + */ + virtual void copy() = 0; + + Item *get_item() { return item; } + /** All of the subclasses should have the same type tag */ + Type type() const override { return COPY_STR_ITEM; } + + const Type_handler *type_handler() const override + { return Type_handler_hybrid_field_type::type_handler(); } + + Field *create_tmp_field_ex(MEM_ROOT *root, TABLE *table, Tmp_field_src *src, + const Tmp_field_param *param) override + { + DBUG_ASSERT(0); + return NULL; + } + void make_send_field(THD *thd, Send_field *field) override + { item->make_send_field(thd, field); } + table_map used_tables() const override { return (table_map) 1L; } + bool const_item() const override { return false; } + bool is_null() override { return null_value; } + bool check_vcol_func_processor(void *arg) override + { + return mark_unsupported_function("copy", arg, VCOL_IMPOSSIBLE); + } + + /* + Override the methods below as pure virtual to make sure all the + sub-classes implement them. + */ + + String *val_str(String*) override = 0; + my_decimal *val_decimal(my_decimal *) override = 0; + double val_real() override = 0; + longlong val_int() override = 0; + int save_in_field(Field *field, bool no_conversions) override = 0; + bool walk(Item_processor processor, bool walk_subquery, void *args) override + { + return (item->walk(processor, walk_subquery, args)) || + (this->*processor)(args); + } +}; + +/** + Implementation of a string cache. + + Uses Item::str_value for storage +*/ +class Item_copy_string : public Item_copy +{ +public: + Item_copy_string(THD *thd, Item *item_arg): Item_copy(thd, item_arg) {} + + String *val_str(String*) override; + my_decimal *val_decimal(my_decimal *) override; + double val_real() override; + longlong val_int() override; + bool get_date(THD *thd, MYSQL_TIME *ltime, date_mode_t fuzzydate) override + { return get_date_from_string(thd, ltime, fuzzydate); } + void copy() override; + int save_in_field(Field *field, bool no_conversions) override; + Item *get_copy(THD *thd) override + { return get_item_copy<Item_copy_string>(thd, this); } +}; + + +/** + We need a separate class Item_copy_timestamp because + TIMESTAMP->string->TIMESTAMP conversion is not round trip safe + near the DST change, e.g. '2010-10-31 02:25:26' can mean: + - my_time_t(1288477526) - summer time in Moscow + - my_time_t(1288481126) - winter time in Moscow, one hour later +*/ +class Item_copy_timestamp: public Item_copy +{ + Timestamp_or_zero_datetime m_value; + bool sane() const { return !null_value || m_value.is_zero_datetime(); } +public: + Item_copy_timestamp(THD *thd, Item *arg): Item_copy(thd, arg) { } + const Type_handler *type_handler() const override + { return &type_handler_timestamp2; } + void copy() override + { + Timestamp_or_zero_datetime_native_null tmp(current_thd, item, false); + null_value= tmp.is_null(); + m_value= tmp.is_null() ? Timestamp_or_zero_datetime() : + Timestamp_or_zero_datetime(tmp); + } + int save_in_field(Field *field, bool) override + { + DBUG_ASSERT(sane()); + if (null_value) + return set_field_to_null(field); + Timestamp_or_zero_datetime_native native(m_value, decimals); + return native.save_in_field(field, decimals); + } + longlong val_int() override + { + DBUG_ASSERT(sane()); + return null_value ? 0 : + m_value.to_datetime(current_thd).to_longlong(); + } + double val_real() override + { + DBUG_ASSERT(sane()); + return null_value ? 0e0 : + m_value.to_datetime(current_thd).to_double(); + } + String *val_str(String *to) override + { + DBUG_ASSERT(sane()); + return null_value ? NULL : + m_value.to_datetime(current_thd).to_string(to, decimals); + } + my_decimal *val_decimal(my_decimal *to) override + { + DBUG_ASSERT(sane()); + return null_value ? NULL : + m_value.to_datetime(current_thd).to_decimal(to); + } + bool get_date(THD *thd, MYSQL_TIME *ltime, date_mode_t fuzzydate) override + { + DBUG_ASSERT(sane()); + bool res= m_value.to_TIME(thd, ltime, fuzzydate); + DBUG_ASSERT(!res); + return null_value || res; + } + bool val_native(THD *thd, Native *to) override + { + DBUG_ASSERT(sane()); + return null_value || m_value.to_native(to, decimals); + } + Item *get_copy(THD *thd) override + { return get_item_copy<Item_copy_timestamp>(thd, this); } +}; + + +/* + Cached_item_XXX objects are not exactly caches. They do the following: + + Each Cached_item_XXX object has + - its source item + - saved value of the source item + - cmp() method that compares the saved value with the current value of the + source item, and if they were not equal saves item's value into the saved + value. + + TODO: add here: + - a way to save the new value w/o comparison + - a way to do less/equal/greater comparison +*/ + +class Cached_item :public Sql_alloc +{ +public: + bool null_value; + Cached_item() :null_value(0) {} + /* + Compare the cached value with the source value. If not equal, copy + the source value to the cache. + @return + true - Not equal + false - Equal + */ + virtual bool cmp(void)=0; + + /* Compare the cached value with the source value, without copying */ + virtual int cmp_read_only()=0; + + virtual ~Cached_item(); /*line -e1509 */ +}; + +class Cached_item_item : public Cached_item +{ +protected: + Item *item; + + Cached_item_item(Item *arg) : item(arg) {} +public: + void fetch_value_from(Item *new_item) + { + Item *save= item; + item= new_item; + cmp(); + item= save; + } +}; + +class Cached_item_str :public Cached_item_item +{ + uint32 value_max_length; + String value,tmp_value; +public: + Cached_item_str(THD *thd, Item *arg); + bool cmp() override; + int cmp_read_only() override; + ~Cached_item_str(); // Deallocate String:s +}; + + +class Cached_item_real :public Cached_item_item +{ + double value; +public: + Cached_item_real(Item *item_par) :Cached_item_item(item_par),value(0.0) {} + bool cmp() override; + int cmp_read_only() override; +}; + +class Cached_item_int :public Cached_item_item +{ + longlong value; +public: + Cached_item_int(Item *item_par) :Cached_item_item(item_par),value(0) {} + bool cmp() override; + int cmp_read_only() override; +}; + + +class Cached_item_decimal :public Cached_item_item +{ + my_decimal value; +public: + Cached_item_decimal(Item *item_par); + bool cmp() override; + int cmp_read_only() override; +}; + +class Cached_item_field :public Cached_item +{ + uchar *buff; + Field *field; + uint length; + +public: + Cached_item_field(THD *thd, Field *arg_field): field(arg_field) + { + field= arg_field; + /* TODO: take the memory allocation below out of the constructor. */ + buff= (uchar*) thd_calloc(thd, length= field->pack_length()); + } + bool cmp() override; + int cmp_read_only() override; +}; + +class Item_default_value : public Item_field +{ + bool vcol_assignment_ok; + void calculate(); +public: + Item *arg= nullptr; + Field *cached_field= nullptr; + Item_default_value(THD *thd, Name_resolution_context *context_arg, Item *a, + bool vcol_assignment_arg) + : Item_field(thd, context_arg), + vcol_assignment_ok(vcol_assignment_arg), arg(a) {} + Type type() const override { return DEFAULT_VALUE_ITEM; } + bool eq(const Item *item, bool binary_cmp) const override; + bool fix_fields(THD *, Item **) override; + void cleanup() override; + void print(String *str, enum_query_type query_type) override; + String *val_str(String *str) override; + double val_real() override; + longlong val_int() override; + my_decimal *val_decimal(my_decimal *decimal_value) override; + bool get_date(THD *thd, MYSQL_TIME *ltime,date_mode_t fuzzydate) override; + bool val_native(THD *thd, Native *to) override; + bool val_native_result(THD *thd, Native *to) override; + + /* Result variants */ + double val_result() override; + longlong val_int_result() override; + String *str_result(String* tmp) override; + my_decimal *val_decimal_result(my_decimal *val) override; + bool val_bool_result() override; + bool is_null_result() override; + bool get_date_result(THD *thd, MYSQL_TIME *ltime, date_mode_t fuzzydate) + override; + + bool send(Protocol *protocol, st_value *buffer) override; + int save_in_field(Field *field_arg, bool no_conversions) override; + bool save_in_param(THD *, Item_param *param) override + { + // It should not be possible to have "EXECUTE .. USING DEFAULT(a)" + DBUG_ASSERT(0); + param->set_default(); + return false; + } + table_map used_tables() const override; + void update_used_tables() override + { + if (field && field->default_value) + field->default_value->expr->update_used_tables(); + } + bool vcol_assignment_allowed_value() const override + { return vcol_assignment_ok; } + Field *get_tmp_table_field() override { return nullptr; } + Item *get_tmp_table_item(THD *) override { return this; } + Item_field *field_for_view_update() override { return nullptr; } + bool update_vcol_processor(void *) override { return false; } + bool check_func_default_processor(void *) override { return true; } + + bool walk(Item_processor processor, bool walk_subquery, void *args) override + { + return (arg && arg->walk(processor, walk_subquery, args)) || + (this->*processor)(args); + } + + Item *transform(THD *thd, Item_transformer transformer, uchar *args) + override; + Field *create_tmp_field_ex(MEM_ROOT *root, TABLE *table, Tmp_field_src *src, + const Tmp_field_param *param) override; +}; + + +class Item_contextually_typed_value_specification: public Item +{ +public: + Item_contextually_typed_value_specification(THD *thd) :Item(thd) + { } + Type type() const override { return CONTEXTUALLY_TYPED_VALUE_ITEM; } + bool vcol_assignment_allowed_value() const override { return true; } + bool eq(const Item *item, bool binary_cmp) const override { return false; } + bool is_evaluable_expression() const override { return false; } + Field *create_tmp_field_ex(MEM_ROOT *, + TABLE *, Tmp_field_src *, + const Tmp_field_param *) override + { + DBUG_ASSERT(0); + return NULL; + } + String *val_str(String *str) override + { + DBUG_ASSERT(0); // never should be called + null_value= true; + return 0; + } + double val_real() override + { + DBUG_ASSERT(0); // never should be called + null_value= true; + return 0.0; + } + longlong val_int() override + { + DBUG_ASSERT(0); // never should be called + null_value= true; + return 0; + } + my_decimal *val_decimal(my_decimal *) override + { + DBUG_ASSERT(0); // never should be called + null_value= true; + return 0; + } + bool get_date(THD *, MYSQL_TIME *, date_mode_t) override + { + DBUG_ASSERT(0); // never should be called + return null_value= true; + } + bool send(Protocol *, st_value *) override + { + DBUG_ASSERT(0); + return true; + } + const Type_handler *type_handler() const override + { + DBUG_ASSERT(0); + return &type_handler_null; + } +}; + + +/* + <default specification> ::= DEFAULT +*/ +class Item_default_specification: + public Item_contextually_typed_value_specification +{ +public: + Item_default_specification(THD *thd) + :Item_contextually_typed_value_specification(thd) + { } + void print(String *str, enum_query_type) override + { + str->append(STRING_WITH_LEN("default")); + } + int save_in_field(Field *field_arg, bool) override + { + return field_arg->save_in_field_default_value(false); + } + bool save_in_param(THD *, Item_param *param) override + { + param->set_default(); + return false; + } + Item *get_copy(THD *thd) override + { return get_item_copy<Item_default_specification>(thd, this); } +}; + + +/** + This class is used as bulk parameter INGNORE representation. + + It just do nothing when assigned to a field + + This is a non-standard MariaDB extension. +*/ + +class Item_ignore_specification: + public Item_contextually_typed_value_specification +{ +public: + Item_ignore_specification(THD *thd) + :Item_contextually_typed_value_specification(thd) + { } + void print(String *str, enum_query_type) override + { + str->append(STRING_WITH_LEN("ignore")); + } + int save_in_field(Field *field_arg, bool) override + { + return field_arg->save_in_field_ignore_value(false); + } + bool save_in_param(THD *, Item_param *param) override + { + param->set_ignore(); + return false; + } + + Item *get_copy(THD *thd) override + { return get_item_copy<Item_ignore_specification>(thd, this); } +}; + + +/* + Item_insert_value -- an implementation of VALUES() function. + You can use the VALUES(col_name) function in the UPDATE clause + to refer to column values from the INSERT portion of the INSERT + ... UPDATE statement. In other words, VALUES(col_name) in the + UPDATE clause refers to the value of col_name that would be + inserted, had no duplicate-key conflict occurred. + In all other places this function returns NULL. +*/ + +class Item_insert_value : public Item_field +{ +public: + Item *arg; + Item_insert_value(THD *thd, Name_resolution_context *context_arg, Item *a) + :Item_field(thd, context_arg), + arg(a) {} + bool eq(const Item *item, bool binary_cmp) const override; + bool fix_fields(THD *, Item **) override; + void print(String *str, enum_query_type query_type) override; + int save_in_field(Field *field_arg, bool no_conversions) override + { + return Item_field::save_in_field(field_arg, no_conversions); + } + Type type() const override { return INSERT_VALUE_ITEM; } + /* + We use RAND_TABLE_BIT to prevent Item_insert_value from + being treated as a constant and precalculated before execution + */ + table_map used_tables() const override { return RAND_TABLE_BIT; } + + Item_field *field_for_view_update() override { return nullptr; } + + bool walk(Item_processor processor, bool walk_subquery, void *args) override + { + return arg->walk(processor, walk_subquery, args) || + (this->*processor)(args); + } + bool check_partition_func_processor(void *) override { return true; } + bool update_vcol_processor(void *) override { return false; } + bool check_vcol_func_processor(void *arg) override + { + return mark_unsupported_function("value()", arg, VCOL_IMPOSSIBLE); + } +}; + + +class Table_triggers_list; + +/* + Represents NEW/OLD version of field of row which is + changed/read in trigger. + + Note: For this item main part of actual binding to Field object happens + not during fix_fields() call (like for Item_field) but right after + parsing of trigger definition, when table is opened, with special + setup_field() call. On fix_fields() stage we simply choose one of + two Field instances representing either OLD or NEW version of this + field. +*/ +class Item_trigger_field : public Item_field, + private Settable_routine_parameter +{ +public: + /* Is this item represents row from NEW or OLD row ? */ + enum row_version_type {OLD_ROW, NEW_ROW}; + row_version_type row_version; + /* Next in list of all Item_trigger_field's in trigger */ + Item_trigger_field *next_trg_field; + /* Index of the field in the TABLE::field array */ + uint field_idx; + /* Pointer to Table_trigger_list object for table of this trigger */ + Table_triggers_list *triggers; + + Item_trigger_field(THD *thd, Name_resolution_context *context_arg, + row_version_type row_ver_arg, + const LEX_CSTRING &field_name_arg, + privilege_t priv, const bool ro) + :Item_field(thd, context_arg, field_name_arg), + row_version(row_ver_arg), field_idx((uint)-1), original_privilege(priv), + want_privilege(priv), table_grants(NULL), read_only (ro) + {} + void setup_field(THD *thd, TABLE *table, GRANT_INFO *table_grant_info); + Type type() const override { return TRIGGER_FIELD_ITEM; } + bool eq(const Item *item, bool binary_cmp) const override; + bool fix_fields(THD *, Item **) override; + void print(String *str, enum_query_type query_type) override; + table_map used_tables() const override { return (table_map)0L; } + Field *get_tmp_table_field() override { return nullptr; } + Item *copy_or_same(THD *) override { return this; } + Item *get_tmp_table_item(THD *thd) override { return copy_or_same(thd); } + void cleanup() override; + +private: + void set_required_privilege(bool rw) override; + bool set_value(THD *thd, sp_rcontext *ctx, Item **it) override; + +public: + Settable_routine_parameter *get_settable_routine_parameter() override + { + return read_only ? nullptr : this; + } + + bool set_value(THD *thd, Item **it) + { + return set_value(thd, NULL, it); + } + +private: + /* + 'want_privilege' holds privileges required to perform operation on + this trigger field (SELECT_ACL if we are going to read it and + UPDATE_ACL if we are going to update it). It is initialized at + parse time but can be updated later if this trigger field is used + as OUT or INOUT parameter of stored routine (in this case + set_required_privilege() is called to appropriately update + want_privilege and cleanup() is responsible for restoring of + original want_privilege once parameter's value is updated). + */ + privilege_t original_privilege; + privilege_t want_privilege; + GRANT_INFO *table_grants; + /* + Trigger field is read-only unless it belongs to the NEW row in a + BEFORE INSERT of BEFORE UPDATE trigger. + */ + bool read_only; +public: + bool unknown_splocal_processor(void *) override { return false; } + bool check_vcol_func_processor(void *arg) override; +}; + + +/** + @todo + Implement the is_null() method for this class. Currently calling is_null() + on any Item_cache object resolves to Item::is_null(), which returns FALSE + for any value. +*/ + +class Item_cache: public Item, + public Type_handler_hybrid_field_type +{ +protected: + Item *example; + /** + Field that this object will get value from. This is used by + index-based subquery engines to detect and remove the equality injected + by IN->EXISTS transformation. + */ + Field *cached_field; + /* + TRUE <=> cache holds value of the last stored item (i.e actual value). + store() stores item to be cached and sets this flag to FALSE. + On the first call of val_xxx function if this flag is set to FALSE the + cache_value() will be called to actually cache value of saved item. + cache_value() will set this flag to TRUE. + */ + bool value_cached; + + table_map used_table_map; +public: + /* + This is set if at least one of the values of a sub query is NULL + Item_cache_row returns this with null_inside(). + For not row items, it's set to the value of null_value + It is set after cache_value() is called. + */ + bool null_value_inside; + + Item_cache(THD *thd): + Item(thd), + Type_handler_hybrid_field_type(&type_handler_string), + example(0), cached_field(0), + value_cached(0), + used_table_map(0) + { + maybe_null= 1; + null_value= 1; + null_value_inside= true; + } +protected: + Item_cache(THD *thd, const Type_handler *handler): + Item(thd), + Type_handler_hybrid_field_type(handler), + example(0), cached_field(0), + value_cached(0), + used_table_map(0) + { + maybe_null= 1; + null_value= 1; + null_value_inside= true; + } + +public: + virtual bool allocate(THD *thd, uint i) { return 0; } + virtual bool setup(THD *thd, Item *item) + { + example= item; + Type_std_attributes::set(item); + if (item->type() == FIELD_ITEM) + cached_field= ((Item_field *)item)->field; + return 0; + }; + + void set_used_tables(table_map map) { used_table_map= map; } + table_map used_tables() const override { return used_table_map; } + Type type() const override { return CACHE_ITEM; } + + const Type_handler *type_handler() const override + { return Type_handler_hybrid_field_type::type_handler(); } + Field *create_tmp_field_ex(MEM_ROOT *root, TABLE *table, Tmp_field_src *src, + const Tmp_field_param *param) override + { + return create_tmp_field_ex_simple(root, table, src, param); + } + + virtual void keep_array() {} + void print(String *str, enum_query_type query_type) override; + bool eq_def(const Field *field) + { + return cached_field ? cached_field->eq_def (field) : FALSE; + } + bool eq(const Item *item, bool binary_cmp) const override + { + return this == item; + } + bool check_vcol_func_processor(void *arg) override + { + if (example) + { + Item::vcol_func_processor_result *res= (Item::vcol_func_processor_result*)arg; + example->check_vcol_func_processor(arg); + /* + Item_cache of a non-deterministic function requires re-fixing + even if the function itself doesn't (e.g. CURRENT_TIMESTAMP) + */ + if (res->errors & VCOL_NOT_STRICTLY_DETERMINISTIC) + res->errors|= VCOL_SESSION_FUNC; + return false; + } + return mark_unsupported_function("cache", arg, VCOL_IMPOSSIBLE); + } + void cleanup() override + { + clear(); + Item::cleanup(); + } + /** + Check if saved item has a non-NULL value. + Will cache value of saved item if not already done. + @return TRUE if cached value is non-NULL. + */ + bool has_value() + { + return (value_cached || cache_value()) && !null_value; + } + + virtual void store(Item *item); + virtual Item *get_item() { return example; } + virtual bool cache_value()= 0; + bool basic_const_item() const override + { return example && example->basic_const_item(); } + virtual void clear() { null_value= TRUE; value_cached= FALSE; } + bool is_null() override { return !has_value(); } + bool is_expensive() override + { + if (value_cached) + return false; + return example->is_expensive(); + } + bool is_expensive_processor(void *arg) override + { + DBUG_ASSERT(example); + if (value_cached) + return false; + return example->is_expensive_processor(arg); + } + virtual void set_null(); + bool walk(Item_processor processor, bool walk_subquery, void *arg) override + { + if (arg == STOP_PTR) + return FALSE; + if (example && example->walk(processor, walk_subquery, arg)) + return TRUE; + return (this->*processor)(arg); + } + Item *safe_charset_converter(THD *thd, CHARSET_INFO *tocs) override; + void split_sum_func2_example(THD *thd, Ref_ptr_array ref_pointer_array, + List<Item> &fields, uint flags) + { + example->split_sum_func2(thd, ref_pointer_array, fields, &example, flags); + } + Item *get_example() const { return example; } + + virtual Item *convert_to_basic_const_item(THD *thd) { return 0; }; + Item *derived_field_transformer_for_having(THD *thd, uchar *) override + { return convert_to_basic_const_item(thd); } + Item *derived_field_transformer_for_where(THD *thd, uchar *) override + { return convert_to_basic_const_item(thd); } + Item *grouping_field_transformer_for_where(THD *thd, uchar *) override + { return convert_to_basic_const_item(thd); } + Item *in_subq_field_transformer_for_where(THD *thd, uchar *) override + { return convert_to_basic_const_item(thd); } + Item *in_subq_field_transformer_for_having(THD *thd, uchar *) override + { return convert_to_basic_const_item(thd); } +}; + + +class Item_cache_int: public Item_cache +{ +protected: + longlong value; +public: + Item_cache_int(THD *thd, const Type_handler *handler): + Item_cache(thd, handler), value(0) {} + + double val_real() override; + longlong val_int() override; + String* val_str(String *str) override; + my_decimal *val_decimal(my_decimal *) override; + bool get_date(THD *thd, MYSQL_TIME *ltime, date_mode_t fuzzydate) override + { return get_date_from_int(thd, ltime, fuzzydate); } + bool cache_value() override; + int save_in_field(Field *field, bool no_conversions) override; + Item *convert_to_basic_const_item(THD *thd) override; + Item *get_copy(THD *thd) override + { return get_item_copy<Item_cache_int>(thd, this); } +}; + + +class Item_cache_year: public Item_cache_int +{ +public: + Item_cache_year(THD *thd, const Type_handler *handler) + :Item_cache_int(thd, handler) { } + bool get_date(THD *thd, MYSQL_TIME *to, date_mode_t mode) + { + return type_handler_year.Item_get_date_with_warn(thd, this, to, mode); + } +}; + + +class Item_cache_temporal: public Item_cache_int +{ +protected: + Item_cache_temporal(THD *thd, const Type_handler *handler); +public: + bool cache_value() override; + bool get_date(THD *thd, MYSQL_TIME *ltime, date_mode_t fuzzydate) override; + int save_in_field(Field *field, bool no_conversions) override; + bool setup(THD *thd, Item *item) override + { + if (Item_cache_int::setup(thd, item)) + return true; + set_if_smaller(decimals, TIME_SECOND_PART_DIGITS); + return false; + } + void store_packed(longlong val_arg, Item *example); + /* + Having a clone_item method tells optimizer that this object + is a constant and need not be optimized further. + Important when storing packed datetime values. + */ + Item *clone_item(THD *thd) override; + Item *convert_to_basic_const_item(THD *thd) override; + virtual Item *make_literal(THD *) =0; +}; + + +class Item_cache_time: public Item_cache_temporal +{ +public: + Item_cache_time(THD *thd) + :Item_cache_temporal(thd, &type_handler_time2) { } + bool cache_value() override; + Item *get_copy(THD *thd) override + { return get_item_copy<Item_cache_time>(thd, this); } + Item *make_literal(THD *) override; + longlong val_datetime_packed(THD *thd) override + { + Datetime::Options_cmp opt(thd); + return has_value() ? Datetime(thd, this, opt).to_packed() : 0; + } + longlong val_time_packed(THD *) override + { + return has_value() ? value : 0; + } + longlong val_int() override + { + return has_value() ? Time(this).to_longlong() : 0; + } + double val_real() override + { + return has_value() ? Time(this).to_double() : 0; + } + String *val_str(String *to) override + { + return has_value() ? Time(this).to_string(to, decimals) : NULL; + } + my_decimal *val_decimal(my_decimal *to) override + { + return has_value() ? Time(this).to_decimal(to) : NULL; + } + bool val_native(THD *thd, Native *to) override + { + return has_value() ? Time(thd, this).to_native(to, decimals) : true; + } +}; + + +class Item_cache_datetime: public Item_cache_temporal +{ +public: + Item_cache_datetime(THD *thd) + :Item_cache_temporal(thd, &type_handler_datetime2) { } + Item *get_copy(THD *thd) override + { return get_item_copy<Item_cache_datetime>(thd, this); } + Item *make_literal(THD *) override; + longlong val_datetime_packed(THD *) override + { + return has_value() ? value : 0; + } + longlong val_time_packed(THD *thd) override + { + return Time(thd, this, Time::Options_cmp(thd)).to_packed(); + } + longlong val_int() override + { + return has_value() ? Datetime(this).to_longlong() : 0; + } + double val_real() override + { + return has_value() ? Datetime(this).to_double() : 0; + } + String *val_str(String *to) override + { + return has_value() ? Datetime(this).to_string(to, decimals) : NULL; + } + my_decimal *val_decimal(my_decimal *to) override + { + return has_value() ? Datetime(this).to_decimal(to) : NULL; + } +}; + + +class Item_cache_date: public Item_cache_temporal +{ +public: + Item_cache_date(THD *thd) + :Item_cache_temporal(thd, &type_handler_newdate) { } + Item *get_copy(THD *thd) override + { return get_item_copy<Item_cache_date>(thd, this); } + Item *make_literal(THD *) override; + longlong val_datetime_packed(THD *) override + { + return has_value() ? value : 0; + } + longlong val_time_packed(THD *thd) override + { + return Time(thd, this, Time::Options_cmp(thd)).to_packed(); + } + longlong val_int() override + { return has_value() ? Date(this).to_longlong() : 0; } + double val_real() override + { return has_value() ? Date(this).to_double() : 0; } + String *val_str(String *to) override + { + return has_value() ? Date(this).to_string(to) : NULL; + } + my_decimal *val_decimal(my_decimal *to) override + { + return has_value() ? Date(this).to_decimal(to) : NULL; + } +}; + + +class Item_cache_timestamp: public Item_cache +{ + Timestamp_or_zero_datetime_native m_native; + Datetime to_datetime(THD *thd); +public: + Item_cache_timestamp(THD *thd) + :Item_cache(thd, &type_handler_timestamp2) { } + Item *get_copy(THD *thd) override + { return get_item_copy<Item_cache_timestamp>(thd, this); } + bool cache_value() override; + String* val_str(String *to) override + { + return to_datetime(current_thd).to_string(to, decimals); + } + my_decimal *val_decimal(my_decimal *to) override + { + return to_datetime(current_thd).to_decimal(to); + } + longlong val_int() override + { + return to_datetime(current_thd).to_longlong(); + } + double val_real() override + { + return to_datetime(current_thd).to_double(); + } + longlong val_datetime_packed(THD *thd) override + { + return to_datetime(thd).to_packed(); + } + longlong val_time_packed(THD *) override + { + DBUG_ASSERT(0); + return 0; + } + bool get_date(THD *thd, MYSQL_TIME *ltime, date_mode_t fuzzydate) override; + int save_in_field(Field *field, bool no_conversions) override; + bool val_native(THD *thd, Native *to) override; +}; + + +class Item_cache_real: public Item_cache +{ +protected: + double value; +public: + Item_cache_real(THD *thd, const Type_handler *h) + :Item_cache(thd, h), + value(0) + {} + double val_real() override; + longlong val_int() override; + my_decimal *val_decimal(my_decimal *) override; + bool get_date(THD *thd, MYSQL_TIME *ltime, date_mode_t fuzzydate) override + { return get_date_from_real(thd, ltime, fuzzydate); } + bool cache_value() override; + Item *convert_to_basic_const_item(THD *thd) override; +}; + + +class Item_cache_double: public Item_cache_real +{ +public: + Item_cache_double(THD *thd) + :Item_cache_real(thd, &type_handler_double) + { } + String* val_str(String *str); + Item *get_copy(THD *thd) + { return get_item_copy<Item_cache_double>(thd, this); } +}; + + +class Item_cache_float: public Item_cache_real +{ +public: + Item_cache_float(THD *thd) + :Item_cache_real(thd, &type_handler_float) + { } + String* val_str(String *str); + Item *get_copy(THD *thd) + { return get_item_copy<Item_cache_float>(thd, this); } +}; + + +class Item_cache_decimal: public Item_cache +{ +protected: + my_decimal decimal_value; +public: + Item_cache_decimal(THD *thd): Item_cache(thd, &type_handler_newdecimal) {} + + double val_real() override; + longlong val_int() override; + String* val_str(String *str) override; + my_decimal *val_decimal(my_decimal *) override; + bool get_date(THD *thd, MYSQL_TIME *to, date_mode_t mode) override + { + return decimal_to_datetime_with_warn(thd, VDec(this).ptr(), to, mode, + NULL, NULL); + } + bool cache_value() override; + Item *convert_to_basic_const_item(THD *thd) override; + Item *get_copy(THD *thd) override + { return get_item_copy<Item_cache_decimal>(thd, this); } +}; + + +class Item_cache_str: public Item_cache +{ + char buffer[STRING_BUFFER_USUAL_SIZE]; + String *value, value_buff; + bool is_varbinary; + +public: + Item_cache_str(THD *thd, const Item *item): + Item_cache(thd, item->type_handler()), value(0), + is_varbinary(item->type() == FIELD_ITEM && + Item_cache_str::field_type() == MYSQL_TYPE_VARCHAR && + !((const Item_field *) item)->field->has_charset()) + { + collation.set(const_cast<DTCollation&>(item->collation)); + } + double val_real() override; + longlong val_int() override; + String* val_str(String *) override; + my_decimal *val_decimal(my_decimal *) override; + bool get_date(THD *thd, MYSQL_TIME *ltime, date_mode_t fuzzydate) override + { return get_date_from_string(thd, ltime, fuzzydate); } + CHARSET_INFO *charset() const { return value->charset(); }; + int save_in_field(Field *field, bool no_conversions) override; + bool cache_value() override; + Item *convert_to_basic_const_item(THD *thd) override; + Item *get_copy(THD *thd) override + { return get_item_copy<Item_cache_str>(thd, this); } +}; + + +class Item_cache_str_for_nullif: public Item_cache_str +{ +public: + Item_cache_str_for_nullif(THD *thd, const Item *item) + :Item_cache_str(thd, item) + { } + Item *safe_charset_converter(THD *thd, CHARSET_INFO *tocs) + { + /** + Item_cache_str::safe_charset_converter() returns a new Item_cache + with Item_func_conv_charset installed on "example". The original + Item_cache is not referenced (neither directly nor recursively) + from the result of Item_cache_str::safe_charset_converter(). + + For NULLIF() purposes we need a different behavior: + we need a new instance of Item_func_conv_charset, + with the original Item_cache referenced in args[0]. See MDEV-9181. + */ + return Item::safe_charset_converter(thd, tocs); + } + Item *get_copy(THD *thd) + { return get_item_copy<Item_cache_str_for_nullif>(thd, this); } +}; + + +class Item_cache_row: public Item_cache +{ + Item_cache **values; + uint item_count; + bool save_array; +public: + Item_cache_row(THD *thd): + Item_cache(thd), values(0), item_count(2), + save_array(0) {} + + /* + 'allocate' used only in row transformer, to preallocate space for row + cache. + */ + bool allocate(THD *thd, uint num) override; + /* + 'setup' is needed only by row => it not called by simple row subselect + (only by IN subselect (in subselect optimizer)) + */ + bool setup(THD *thd, Item *item) override; + void store(Item *item) override; + void illegal_method_call(const char *); + void make_send_field(THD *, Send_field *) override + { + illegal_method_call("make_send_field"); + }; + double val_real() override + { + illegal_method_call("val"); + return 0; + }; + longlong val_int() override + { + illegal_method_call("val_int"); + return 0; + }; + String *val_str(String *) override + { + illegal_method_call("val_str"); + return nullptr; + }; + my_decimal *val_decimal(my_decimal *) override + { + illegal_method_call("val_decimal"); + return nullptr; + }; + bool get_date(THD *thd, MYSQL_TIME *ltime, date_mode_t fuzzydate) override + { + illegal_method_call("val_decimal"); + return true; + } + + uint cols() const override { return item_count; } + Item *element_index(uint i) override { return values[i]; } + Item **addr(uint i) override { return (Item **) (values + i); } + bool check_cols(uint c) override; + bool null_inside() override; + void bring_value() override; + void keep_array() override { save_array= 1; } + void cleanup() override + { + DBUG_ENTER("Item_cache_row::cleanup"); + Item_cache::cleanup(); + if (save_array) + bzero(values, item_count*sizeof(Item**)); + else + values= 0; + DBUG_VOID_RETURN; + } + bool cache_value() override; + void set_null() override; + Item *get_copy(THD *thd) override + { return get_item_copy<Item_cache_row>(thd, this); } +}; + + +/* + Item_type_holder used to store type. name, length of Item for UNIONS & + derived tables. + + Item_type_holder do not need cleanup() because its time of live limited by + single SP/PS execution. +*/ +class Item_type_holder: public Item, + public Type_handler_hybrid_field_type +{ +protected: + const TYPELIB *enum_set_typelib; +public: + Item_type_holder(THD *thd, Item *item) + :Item(thd, item), + Type_handler_hybrid_field_type(item->real_type_handler()), + enum_set_typelib(0) + { + DBUG_ASSERT(item->is_fixed()); + maybe_null= item->maybe_null; + } + Item_type_holder(THD *thd, + Item *item, + const Type_handler *handler, + const Type_all_attributes *attr, + bool maybe_null_arg) + :Item(thd), + Type_handler_hybrid_field_type(handler), + enum_set_typelib(attr->get_typelib()) + { + name= item->name; + Type_std_attributes::set(*attr); + maybe_null= maybe_null_arg; + common_flags= item->common_flags; + } + + const Type_handler *type_handler() const override + { + return Type_handler_hybrid_field_type::type_handler()-> + type_handler_for_item_field(); + } + const Type_handler *real_type_handler() const override + { + return Type_handler_hybrid_field_type::type_handler(); + } + + Type type() const override { return TYPE_HOLDER; } + const TYPELIB *get_typelib() const override { return enum_set_typelib; } + /* + When handling a query like this: + VALUES ('') UNION VALUES( _utf16 0x0020 COLLATE utf16_bin); + Item_type_holder can be passed to + Type_handler_xxx::Item_hybrid_func_fix_attributes() + We don't want the latter to perform character set conversion of a + Item_type_holder by calling its val_str(), which calls DBUG_ASSERT(0). + Let's override const_item() and is_expensive() to avoid this. + Note, Item_hybrid_func_fix_attributes() could probably + have a new argument to distinguish what we need: + - (a) aggregate data type attributes only + - (b) install converters after attribute aggregation + So st_select_lex_unit::join_union_type_attributes() could + ask it to do (a) only, without (b). + */ + bool const_item() const override { return false; } + bool is_expensive() override { return true; } + double val_real() override; + longlong val_int() override; + my_decimal *val_decimal(my_decimal *) override; + String *val_str(String*) override; + bool get_date(THD *thd, MYSQL_TIME *ltime, date_mode_t fuzzydate) override; + Field *create_tmp_field_ex(MEM_ROOT *root, TABLE *table, Tmp_field_src *src, + const Tmp_field_param *param) override + { + return Item_type_holder::real_type_handler()-> + make_and_init_table_field(root, &name, Record_addr(maybe_null), + *this, table); + } + Item* get_copy(THD *) override { return nullptr; } + +}; + + +class st_select_lex; +void mark_select_range_as_dependent(THD *thd, + st_select_lex *last_select, + st_select_lex *current_sel, + Field *found_field, Item *found_item, + Item_ident *resolved_item, + bool suppress_warning_output); + +extern Cached_item *new_Cached_item(THD *thd, Item *item, + bool pass_through_ref); +extern Item_result item_cmp_type(Item_result a,Item_result b); +extern void resolve_const_item(THD *thd, Item **ref, Item *cmp_item); +extern int stored_field_cmp_to_item(THD *thd, Field *field, Item *item); + +extern const String my_null_string; + +/** + Interface for Item iterator +*/ + +class Item_iterator +{ +public: + /** + Shall set this iterator to the position before the first item + + @note + This method also may perform some other initialization actions like + allocation of certain resources. + */ + virtual void open()= 0; + /** + Shall return the next Item (or NULL if there is no next item) and + move pointer to position after it. + */ + virtual Item *next()= 0; + /** + Shall force iterator to free resources (if it holds them) + + @note + One should not use the iterator without open() call after close() + */ + virtual void close()= 0; + + virtual ~Item_iterator() {} +}; + + +/** + Item iterator over List_iterator_fast for Item references +*/ + +class Item_iterator_ref_list: public Item_iterator +{ + List_iterator<Item*> list; +public: + Item_iterator_ref_list(List_iterator<Item*> &arg_list): + list(arg_list) {} + void open() { list.rewind(); } + Item *next() { return *(list++); } + void close() {} +}; + + +/** + Item iterator over List_iterator_fast for Items +*/ + +class Item_iterator_list: public Item_iterator +{ + List_iterator<Item> list; +public: + Item_iterator_list(List_iterator<Item> &arg_list): + list(arg_list) {} + void open() { list.rewind(); } + Item *next() { return (list++); } + void close() {} +}; + + +/** + Item iterator over Item interface for rows +*/ + +class Item_iterator_row: public Item_iterator +{ + Item *base_item; + uint current; +public: + Item_iterator_row(Item *base) : base_item(base), current(0) {} + void open() { current= 0; } + Item *next() + { + if (current >= base_item->cols()) + return NULL; + return base_item->element_index(current++); + } + void close() {} +}; + + +/* + It's used in ::fix_fields() methods of LIKE and JSON_SEARCH + functions to handle the ESCAPE parameter. + This parameter is quite non-standard so the specific function. +*/ +bool fix_escape_item(THD *thd, Item *escape_item, String *tmp_str, + bool escape_used_in_parsing, CHARSET_INFO *cmp_cs, + int *escape); + +inline bool Virtual_column_info::is_equal(const Virtual_column_info* vcol) const +{ + return type_handler() == vcol->type_handler() + && stored_in_db == vcol->is_stored() + && expr->eq(vcol->expr, true); +} + +inline void Virtual_column_info::print(String* str) +{ + expr->print_for_table_def(str); +} + +inline bool TABLE::mark_column_with_deps(Field *field) +{ + bool res; + if (!(res= bitmap_fast_test_and_set(read_set, field->field_index))) + { + if (field->vcol_info) + mark_virtual_column_deps(field); + } + return res; +} + +inline bool TABLE::mark_virtual_column_with_deps(Field *field) +{ + bool res; + DBUG_ASSERT(field->vcol_info); + if (!(res= bitmap_fast_test_and_set(read_set, field->field_index))) + mark_virtual_column_deps(field); + return res; +} + +inline void TABLE::mark_virtual_column_deps(Field *field) +{ + DBUG_ASSERT(field->vcol_info); + DBUG_ASSERT(field->vcol_info->expr); + field->vcol_info->expr->walk(&Item::register_field_in_read_map, 1, 0); +} + +inline void TABLE::use_all_stored_columns() +{ + bitmap_set_all(read_set); + if (Field **vf= vfield) + for (; *vf; vf++) + bitmap_clear_bit(read_set, (*vf)->field_index); +} + +#endif /* SQL_ITEM_INCLUDED */ |