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Diffstat (limited to 'sql/sql_view.cc')
| -rw-r--r-- | sql/sql_view.cc | 2244 |
1 files changed, 2244 insertions, 0 deletions
diff --git a/sql/sql_view.cc b/sql/sql_view.cc new file mode 100644 index 00000000..b7f64389 --- /dev/null +++ b/sql/sql_view.cc @@ -0,0 +1,2244 @@ +/* Copyright (c) 2004, 2013, Oracle and/or its affiliates. + Copyright (c) 2011, 2016, 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 +*/ + +#define MYSQL_LEX 1 +#include "mariadb.h" /* NO_EMBEDDED_ACCESS_CHECKS */ +#include "sql_priv.h" +#include "unireg.h" +#include "sql_view.h" +#include "sql_base.h" // find_table_in_global_list, lock_table_names +#include "sql_parse.h" // sql_parse +#include "sql_cache.h" // query_cache_* +#include "lock.h" // MYSQL_OPEN_SKIP_TEMPORARY +#include "sql_show.h" // append_identifier +#include "sql_table.h" // build_table_filename +#include "sql_db.h" // mysql_opt_change_db, mysql_change_db +#include "sql_select.h" +#include "parse_file.h" +#include "sp_head.h" +#include "sp.h" +#include "sp_cache.h" +#include "datadict.h" // dd_frm_is_view() +#include "sql_derived.h" +#include "opt_trace.h" +#include "wsrep_mysqld.h" + +#define MD5_BUFF_LENGTH 33 + +const LEX_CSTRING view_type= { STRING_WITH_LEN("VIEW") }; + +static int mysql_register_view(THD *, TABLE_LIST *, enum_view_create_mode); + +/* + Make a unique name for an anonymous view column + SYNOPSIS + target reference to the item for which a new name has to be made + item_list list of items within which we should check uniqueness of + the created name + last_element the last element of the list above + + NOTE + Unique names are generated by adding 'My_exp_' to the old name of the + column. In case the name that was created this way already exists, we + add a numeric postfix to its end (i.e. "1") and increase the number + until the name becomes unique. If the generated name is longer than + NAME_LEN, it is truncated. +*/ + +static void make_unique_view_field_name(THD *thd, Item *target, + List<Item> &item_list, + Item *last_element) +{ + const char *name= (target->orig_name ? + target->orig_name : + target->name.str); + size_t name_len; + uint attempt; + char buff[NAME_LEN+1]; + List_iterator_fast<Item> itc(item_list); + + for (attempt= 0;; attempt++) + { + Item *check; + bool ok= TRUE; + + if (attempt) + name_len= my_snprintf(buff, NAME_LEN, "My_exp_%d_%s", attempt, name); + else + name_len= my_snprintf(buff, NAME_LEN, "My_exp_%s", name); + + do + { + check= itc++; + if (check != target && + my_strcasecmp(system_charset_info, buff, check->name.str) == 0) + { + ok= FALSE; + break; + } + } while (check != last_element); + if (ok) + break; + itc.rewind(); + } + + target->orig_name= target->name.str; + target->set_name(thd, buff, name_len, system_charset_info); +} + + +/* + Check if items with same names are present in list and possibly + generate unique names for them. + + SYNOPSIS + item_list list of Items which should be checked for duplicates + gen_unique_view_name flag: generate unique name or return with error when + duplicate names are found. + + DESCRIPTION + This function is used on view creation and preparation of derived tables. + It checks item_list for items with duplicate names. If it founds two + items with same name and conversion to unique names isn't allowed, or + names for both items are set by user - function fails. + Otherwise it generates unique name for one item with autogenerated name + using make_unique_view_field_name() + + RETURN VALUE + FALSE no duplicate names found, or they are converted to unique ones + TRUE duplicate names are found and they can't be converted or conversion + isn't allowed +*/ + +bool check_duplicate_names(THD *thd, List<Item> &item_list, bool gen_unique_view_name) +{ + Item *item; + List_iterator_fast<Item> it(item_list); + List_iterator_fast<Item> itc(item_list); + DBUG_ENTER("check_duplicate_names"); + + while ((item= it++)) + { + Item *check; + /* treat underlying fields like set by user names */ + if (item->real_item()->type() == Item::FIELD_ITEM) + item->common_flags&= ~IS_AUTO_GENERATED_NAME; + itc.rewind(); + while ((check= itc++) && check != item) + { + if (lex_string_cmp(system_charset_info, &item->name, &check->name) == 0) + { + if (!gen_unique_view_name) + goto err; + if (item->is_autogenerated_name()) + make_unique_view_field_name(thd, item, item_list, item); + else if (check->is_autogenerated_name()) + make_unique_view_field_name(thd, check, item_list, item); + else + goto err; + } + } + } + DBUG_RETURN(FALSE); + +err: + my_error(ER_DUP_FIELDNAME, MYF(0), item->name.str); + DBUG_RETURN(TRUE); +} + + +/** + Check if auto generated column names are conforming and + possibly generate a conforming name for them if not. + + @param item_list List of Items which should be checked +*/ + +void make_valid_column_names(THD *thd, List<Item> &item_list) +{ + Item *item; + size_t name_len; + List_iterator_fast<Item> it(item_list); + char buff[NAME_LEN]; + DBUG_ENTER("make_valid_column_names"); + + for (uint column_no= 1; (item= it++); column_no++) + { + if (!item->is_autogenerated_name() || !check_column_name(item->name.str)) + continue; + name_len= my_snprintf(buff, NAME_LEN, "Name_exp_%u", column_no); + item->orig_name= item->name.str; + item->set_name(thd, buff, name_len, system_charset_info); + } + + DBUG_VOID_RETURN; +} + + +/* + Fill defined view parts + + SYNOPSIS + fill_defined_view_parts() + thd current thread. + view view to operate on + + DESCRIPTION + This function will initialize the parts of the view + definition that are not specified in ALTER VIEW + to their values from CREATE VIEW. + The view must be opened to get its definition. + We use a copy of the view when opening because we want + to preserve the original view instance. + + RETURN VALUE + TRUE can't open table + FALSE success +*/ +static bool +fill_defined_view_parts (THD *thd, TABLE_LIST *view) +{ + LEX *lex= thd->lex; + TABLE_LIST decoy; + + decoy= *view; + decoy.mdl_request.key.mdl_key_init(&view->mdl_request.key); + if (tdc_open_view(thd, &decoy, OPEN_VIEW_NO_PARSE)) + return TRUE; + + if (!lex->definer) + { + view->definer.host= decoy.definer.host; + view->definer.user= decoy.definer.user; + lex->definer= &view->definer; + } + if (lex->create_view->algorithm == VIEW_ALGORITHM_INHERIT) + lex->create_view->algorithm= (uint8) decoy.algorithm; + if (lex->create_view->suid == VIEW_SUID_DEFAULT) + lex->create_view->suid= decoy.view_suid ? + VIEW_SUID_DEFINER : VIEW_SUID_INVOKER; + + return FALSE; +} + +#ifndef NO_EMBEDDED_ACCESS_CHECKS + +/** + @brief CREATE VIEW privileges pre-check. + + @param thd thread handler + @param tables tables used in the view + @param views views to create + @param mode VIEW_CREATE_NEW, VIEW_ALTER, VIEW_CREATE_OR_REPLACE + + @retval FALSE Operation was a success. + @retval TRUE An error occurred. +*/ + +bool create_view_precheck(THD *thd, TABLE_LIST *tables, TABLE_LIST *view, + enum_view_create_mode mode) +{ + LEX *lex= thd->lex; + /* first table in list is target VIEW name => cut off it */ + TABLE_LIST *tbl; + SELECT_LEX *select_lex= lex->first_select_lex(); + SELECT_LEX *sl; + bool res= TRUE; + DBUG_ENTER("create_view_precheck"); + + /* + Privilege check for view creation: + - user has CREATE VIEW privilege on view table + - user has DROP privilege in case of ALTER VIEW or CREATE OR REPLACE + VIEW + - user has some (SELECT/UPDATE/INSERT/DELETE) privileges on columns of + underlying tables used on top of SELECT list (because it can be + (theoretically) updated, so it is enough to have UPDATE privilege on + them, for example) + - user has SELECT privilege on columns used in expressions of VIEW select + - for columns of underly tables used on top of SELECT list also will be + checked that we have not more privileges on correspondent column of view + table (i.e. user will not get some privileges by view creation) + */ + if ((check_access(thd, CREATE_VIEW_ACL, view->db.str, + &view->grant.privilege, + &view->grant.m_internal, + 0, 0) || + check_grant(thd, CREATE_VIEW_ACL, view, FALSE, 1, FALSE)) || + (mode != VIEW_CREATE_NEW && + (check_access(thd, DROP_ACL, view->db.str, + &view->grant.privilege, + &view->grant.m_internal, + 0, 0) || + check_grant(thd, DROP_ACL, view, FALSE, 1, FALSE)))) + goto err; + + for (sl= select_lex; sl; sl= sl->next_select()) + { + for (tbl= sl->get_table_list(); tbl; tbl= tbl->next_local) + { + if (!tbl->with && tbl->select_lex) + tbl->with= tbl->select_lex->find_table_def_in_with_clauses(tbl); + /* + Ensure that we have some privileges on this table, more strict check + will be done on column level after preparation, + */ + if (check_some_access(thd, VIEW_ANY_ACL, tbl)) + { + my_error(ER_TABLEACCESS_DENIED_ERROR, MYF(0), + "ANY", thd->security_ctx->priv_user, + thd->security_ctx->priv_host, tbl->table_name.str); + goto err; + } + /* + Mark this table as a table which will be checked after the prepare + phase + */ + tbl->table_in_first_from_clause= 1; + + /* + We need to check only SELECT_ACL for all normal fields, fields for + which we need "any" (SELECT/UPDATE/INSERT/DELETE) privilege will be + checked later + */ + tbl->grant.want_privilege= SELECT_ACL; + /* + Make sure that all rights are loaded to the TABLE::grant field. + + tbl->table_name will be correct name of table because VIEWs are + not opened yet. + */ + fill_effective_table_privileges(thd, &tbl->grant, tbl->db.str, tbl->table_name.str); + } + } + + { + /* check tables of subqueries */ + for (tbl= tables; tbl; tbl= tbl->next_global) + { + if (!tbl->table_in_first_from_clause) + { + if (check_single_table_access(thd, SELECT_ACL, tbl, FALSE)) + { + tbl->hide_view_error(thd); + goto err; + } + } + } + } + /* + Mark fields for special privilege check ("any" privilege) + */ + for (sl= select_lex; sl; sl= sl->next_select()) + { + List_iterator_fast<Item> it(sl->item_list); + Item *item; + while ((item= it++)) + { + Item_field *field; + if ((field= item->field_for_view_update())) + { + /* + any_privileges may be reset later by the Item_field::set_field + method in case of a system temporary table. + */ + field->any_privileges= 1; + } + } + } + + res= FALSE; + +err: + DBUG_RETURN(res || thd->is_error()); +} + +#else + +bool create_view_precheck(THD *thd, TABLE_LIST *tables, TABLE_LIST *view, + enum_view_create_mode mode) +{ + return FALSE; +} + +#endif + + +/** + @brief Creating/altering VIEW procedure + + @param thd thread handler + @param views views to create + @param mode VIEW_CREATE_NEW, VIEW_ALTER, VIEW_CREATE_OR_REPLACE + + @note This function handles both create and alter view commands. + + @retval FALSE Operation was a success. + @retval TRUE An error occurred. +*/ + +bool mysql_create_view(THD *thd, TABLE_LIST *views, + enum_view_create_mode mode) +{ + LEX *lex= thd->lex; + bool link_to_local; + /* first table in list is target VIEW name => cut off it */ + TABLE_LIST *view= lex->unlink_first_table(&link_to_local); + TABLE_LIST *tables= lex->query_tables; + TABLE_LIST *tbl; + SELECT_LEX *select_lex= lex->first_select_lex(); + SELECT_LEX *sl; + SELECT_LEX_UNIT *unit= &lex->unit; + bool res= FALSE; + DBUG_ENTER("mysql_create_view"); + + /* This is ensured in the parser. */ + DBUG_ASSERT(!lex->proc_list.first && !lex->result && + !lex->param_list.elements); + + /* + We can't allow taking exclusive meta-data locks of unlocked view under + LOCK TABLES since this might lead to deadlock. Since at the moment we + can't really lock view with LOCK TABLES we simply prohibit creation/ + alteration of views under LOCK TABLES. + */ + + if (thd->locked_tables_mode) + { + my_error(ER_LOCK_OR_ACTIVE_TRANSACTION, MYF(0)); + res= TRUE; + goto err; + } + + if ((res= create_view_precheck(thd, tables, view, mode))) + goto err; + + lex->link_first_table_back(view, link_to_local); + view->open_type= OT_BASE_ONLY; + + WSREP_TO_ISOLATION_BEGIN(WSREP_MYSQL_DB, NULL, NULL); + + /* + ignore lock specs for CREATE statement + */ + if (lex->current_select->lock_type != TL_READ_DEFAULT) + { + lex->current_select->set_lock_for_tables(TL_READ_DEFAULT, false); + view->mdl_request.set_type(MDL_EXCLUSIVE); + } + + if (thd->open_temporary_tables(lex->query_tables) || + open_and_lock_tables(thd, lex->query_tables, TRUE, 0)) + { + res= TRUE; + goto err_no_relink; + } + +#ifdef WITH_WSREP + if(!wsrep_should_replicate_ddl_iterate(thd, static_cast<const TABLE_LIST *>(tables))) + { + res= TRUE; + goto err_no_relink; + } +#endif + + view= lex->unlink_first_table(&link_to_local); + + if (check_db_dir_existence(view->db.str)) + { + my_error(ER_BAD_DB_ERROR, MYF(0), view->db.str); + res= TRUE; + goto err; + } + + if (mode == VIEW_ALTER && fill_defined_view_parts(thd, view)) + { + res= TRUE; + goto err; + } + + if (lex->limit_rows_examined) + { + /* + LIMIT ROWS EXAMINED is not supported inside views to avoid complicated + side-effects and semantics of the clause. + */ + my_error(ER_NOT_SUPPORTED_YET, MYF(0), "LIMIT ROWS EXAMINED inside views"); + res= TRUE; + goto err; + } + + sp_cache_invalidate(); + if (sp_process_definer(thd)) + goto err; + + /* + check that tables are not temporary and this VIEW do not used in query + (it is possible with ALTERing VIEW). + open_and_lock_tables can change the value of tables, + e.g. it may happen if before the function call tables was equal to 0. + */ + for (tbl= lex->query_tables; tbl; tbl= tbl->next_global) + { + /* is this table view and the same view which we creates now? */ + if (tbl->view && + cmp(&tbl->view_db, &view->db) == 0 && + cmp(&tbl->view_name, &view->table_name) == 0) + { + my_error(ER_NO_SUCH_TABLE, MYF(0), tbl->view_db.str, tbl->view_name.str); + res= TRUE; + goto err; + } + + /* + tbl->table can be NULL when tbl is a placeholder for a view + that is indirectly referenced via a stored function from the + view being created. We don't check these indirectly + referenced views in CREATE VIEW so they don't have table + object. + */ + if (tbl->table) + { + /* is this table temporary and is not view? */ + if (tbl->table->s->tmp_table != NO_TMP_TABLE && !tbl->view && + !tbl->schema_table) + { + my_error(ER_VIEW_SELECT_TMPTABLE, MYF(0), tbl->alias.str); + res= TRUE; + goto err; + } + /* + Copy the privileges of the underlying VIEWs which were filled by + fill_effective_table_privileges + (they were not copied at derived tables processing) + */ + tbl->table->grant.privilege= tbl->grant.privilege; + } + } + + /* prepare select to resolve all fields */ + lex->context_analysis_only|= CONTEXT_ANALYSIS_ONLY_VIEW; + if (unit->prepare(unit->derived, 0, 0)) + { + /* + some errors from prepare are reported to user, if is not then + it will be checked after err: label + */ + res= TRUE; + goto err; + } + + /* view list (list of view fields names) */ + if (lex->view_list.elements) + { + List_iterator_fast<Item> it(select_lex->item_list); + List_iterator_fast<LEX_CSTRING> nm(lex->view_list); + Item *item; + LEX_CSTRING *name; + + if (lex->view_list.elements != select_lex->item_list.elements) + { + my_message(ER_VIEW_WRONG_LIST, ER_THD(thd, ER_VIEW_WRONG_LIST), MYF(0)); + res= TRUE; + goto err; + } + while ((item= it++, name= nm++)) + { + item->set_name(thd, *name); + item->common_flags&= ~IS_AUTO_GENERATED_NAME; + } + } + + /* Check if the auto generated column names are conforming. */ + for (sl= select_lex; sl; sl= sl->next_select()) + make_valid_column_names(thd, sl->item_list); + + if (check_duplicate_names(thd, select_lex->item_list, 1)) + { + res= TRUE; + goto err; + } + +#ifndef NO_EMBEDDED_ACCESS_CHECKS + /* + Compare/check grants on view with grants of underlying tables + */ + + fill_effective_table_privileges(thd, &view->grant, view->db.str, + view->table_name.str); + + /* + Make sure that the current user does not have more column-level privileges + on the newly created view than he/she does on the underlying + tables. E.g. it must not be so that the user has UPDATE privileges on a + view column of he/she doesn't have it on the underlying table's + corresponding column. In that case, return an error for CREATE VIEW. + */ + { + Item *report_item= NULL; + /* + This will hold the intersection of the priviliges on all columns in the + view. + */ + privilege_t final_priv(VIEW_ANY_ACL); + + for (sl= select_lex; sl; sl= sl->next_select()) + { + DBUG_ASSERT(view->db.str); /* Must be set in the parser */ + List_iterator_fast<Item> it(sl->item_list); + Item *item; + while ((item= it++)) + { + Item_field *fld= item->field_for_view_update(); + privilege_t priv(get_column_grant(thd, &view->grant, view->db.str, + view->table_name.str, + item->name.str) & + VIEW_ANY_ACL); + + if (!fld) + continue; + TABLE_SHARE *s= fld->field->table->s; + const Lex_ident field_name= fld->field->field_name; + if (s->tmp_table || + (s->versioned && + (field_name.streq(s->vers_start_field()->field_name) || + field_name.streq(s->vers_end_field()->field_name)))) + { + continue; + } + + final_priv&= fld->have_privileges; + + if (~fld->have_privileges & priv) + report_item= item; + } + } + + if (!final_priv && report_item) + { + my_error(ER_COLUMNACCESS_DENIED_ERROR, MYF(0), + "create view", thd->security_ctx->priv_user, + thd->security_ctx->priv_host, report_item->name.str, + view->table_name.str); + res= TRUE; + goto err; + } + } +#endif + + res= mysql_register_view(thd, view, mode); + + /* + View TABLE_SHARE must be removed from the table definition cache in order to + make ALTER VIEW work properly. Otherwise, we would not be able to detect + meta-data changes after ALTER VIEW. + */ + + if (!res) + tdc_remove_table(thd, view->db.str, view->table_name.str); + + if (!res && mysql_bin_log.is_open()) + { + StringBuffer<128> buff(thd->variables.character_set_client); + DBUG_ASSERT(buff.charset()->mbminlen == 1); + const LEX_CSTRING command[3]= + {{ STRING_WITH_LEN("CREATE ") }, + { STRING_WITH_LEN("ALTER ") }, + { STRING_WITH_LEN("CREATE OR REPLACE ") }}; + + buff.append(&command[thd->lex->create_view->mode]); + view_store_options(thd, views, &buff); + buff.append(STRING_WITH_LEN("VIEW ")); + + /* Appending IF NOT EXISTS if present in the query */ + if (lex->create_info.if_not_exists()) + buff.append(STRING_WITH_LEN("IF NOT EXISTS ")); + + /* Test if user supplied a db (ie: we did not use thd->db) */ + if (views->db.str && views->db.str[0] && + (thd->db.str == NULL || cmp(&views->db, &thd->db))) + { + append_identifier(thd, &buff, &views->db); + buff.append('.'); + } + append_identifier(thd, &buff, &views->table_name); + if (lex->view_list.elements) + { + List_iterator_fast<LEX_CSTRING> names(lex->view_list); + LEX_CSTRING *name; + int i; + + for (i= 0; (name= names++); i++) + { + buff.append(i ? ", " : "("); + append_identifier(thd, &buff, name); + } + buff.append(')'); + } + buff.append(STRING_WITH_LEN(" AS ")); + /* views->source doesn't end with \0 */ + buff.append(views->source.str, views->source.length); + + int errcode= query_error_code(thd, TRUE); + /* + Don't log any unsafe warnings for CREATE VIEW as it's safely replicated + with statement based replication + */ + thd->reset_unsafe_warnings(); + if (thd->binlog_query(THD::STMT_QUERY_TYPE, + buff.ptr(), buff.length(), FALSE, FALSE, FALSE, + errcode) > 0) + res= TRUE; + } + + if (mode != VIEW_CREATE_NEW) + query_cache_invalidate3(thd, view, 0); + if (res) + goto err; + + my_ok(thd); + lex->link_first_table_back(view, link_to_local); + DBUG_RETURN(0); + +#ifdef WITH_WSREP +wsrep_error_label: + res= true; + goto err_no_relink; +#endif + +err: + lex->link_first_table_back(view, link_to_local); +err_no_relink: + unit->cleanup(); + DBUG_RETURN(res || thd->is_error()); +} + + +static void make_view_filename(LEX_CSTRING *dir, char *dir_buff, + size_t dir_buff_len, + LEX_CSTRING *path, char *path_buff, + size_t path_buff_len, + LEX_CSTRING *file, + TABLE_LIST *view) +{ + /* print file name */ + dir->length= build_table_filename(dir_buff, dir_buff_len - 1, + view->db.str, "", "", 0); + dir->str= dir_buff; + + path->length= build_table_filename(path_buff, path_buff_len - 1, + view->db.str, view->table_name.str, reg_ext, 0); + path->str= path_buff; + + file->str= path->str + dir->length; + file->length= path->length - dir->length; +} + +/* number of required parameters for making view */ +static const int required_view_parameters= 15; + +/* + table of VIEW .frm field descriptors + + Note that one should NOT change the order for this, as it's used by + parse() +*/ +static File_option view_parameters[]= +{{{ STRING_WITH_LEN("query")}, + my_offsetof(TABLE_LIST, select_stmt), + FILE_OPTIONS_ESTRING}, + {{ STRING_WITH_LEN("md5")}, + my_offsetof(TABLE_LIST, md5), + FILE_OPTIONS_STRING}, + {{ STRING_WITH_LEN("updatable")}, + my_offsetof(TABLE_LIST, updatable_view), + FILE_OPTIONS_ULONGLONG}, + {{ STRING_WITH_LEN("algorithm")}, + my_offsetof(TABLE_LIST, algorithm), + FILE_OPTIONS_VIEW_ALGO}, + {{ STRING_WITH_LEN("definer_user")}, + my_offsetof(TABLE_LIST, definer.user), + FILE_OPTIONS_STRING}, + {{ STRING_WITH_LEN("definer_host")}, + my_offsetof(TABLE_LIST, definer.host), + FILE_OPTIONS_STRING}, + {{ STRING_WITH_LEN("suid")}, + my_offsetof(TABLE_LIST, view_suid), + FILE_OPTIONS_ULONGLONG}, + {{ STRING_WITH_LEN("with_check_option")}, + my_offsetof(TABLE_LIST, with_check), + FILE_OPTIONS_ULONGLONG}, + {{ STRING_WITH_LEN("timestamp")}, + my_offsetof(TABLE_LIST, timestamp), + FILE_OPTIONS_TIMESTAMP}, + {{ STRING_WITH_LEN("create-version")}, + my_offsetof(TABLE_LIST, file_version), + FILE_OPTIONS_ULONGLONG}, + {{ STRING_WITH_LEN("source")}, + my_offsetof(TABLE_LIST, source), + FILE_OPTIONS_ESTRING}, + {{(char*) STRING_WITH_LEN("client_cs_name")}, + my_offsetof(TABLE_LIST, view_client_cs_name), + FILE_OPTIONS_STRING}, + {{(char*) STRING_WITH_LEN("connection_cl_name")}, + my_offsetof(TABLE_LIST, view_connection_cl_name), + FILE_OPTIONS_STRING}, + {{(char*) STRING_WITH_LEN("view_body_utf8")}, + my_offsetof(TABLE_LIST, view_body_utf8), + FILE_OPTIONS_ESTRING}, + {{ STRING_WITH_LEN("mariadb-version")}, + my_offsetof(TABLE_LIST, mariadb_version), + FILE_OPTIONS_ULONGLONG}, + {{NullS, 0}, 0, + FILE_OPTIONS_STRING} +}; + +static LEX_CSTRING view_file_type[]= {{STRING_WITH_LEN("VIEW") }}; + + +int mariadb_fix_view(THD *thd, TABLE_LIST *view, bool wrong_checksum, + bool swap_alg) +{ + char dir_buff[FN_REFLEN + 1], path_buff[FN_REFLEN + 1]; + LEX_CSTRING dir, file, path; + DBUG_ENTER("mariadb_fix_view"); + + if (!wrong_checksum && view->mariadb_version) + DBUG_RETURN(HA_ADMIN_OK); + + make_view_filename(&dir, dir_buff, sizeof(dir_buff), + &path, path_buff, sizeof(path_buff), + &file, view); + /* init timestamp */ + if (!view->timestamp.str) + view->timestamp.str= view->timestamp_buffer; + + if (swap_alg && view->algorithm != VIEW_ALGORITHM_UNDEFINED) + { + DBUG_ASSERT(view->algorithm == VIEW_ALGORITHM_MERGE || + view->algorithm == VIEW_ALGORITHM_TMPTABLE); + if (view->algorithm == VIEW_ALGORITHM_MERGE) + view->algorithm= VIEW_ALGORITHM_TMPTABLE; + else + view->algorithm= VIEW_ALGORITHM_MERGE; + } + else + swap_alg= 0; + if (wrong_checksum) + { + if (view->md5.length != 32) + { + if ((view->md5.str= (char *)thd->alloc(32 + 1)) == NULL) + DBUG_RETURN(HA_ADMIN_FAILED); + } + view->calc_md5(view->md5.str); + view->md5.length= 32; + } + view->mariadb_version= MYSQL_VERSION_ID; + + if (sql_create_definition_file(&dir, &file, view_file_type, + (uchar*)view, view_parameters)) + { + sql_print_error("View '%-.192s'.'%-.192s': algorithm swap error.", + view->db.str, view->table_name.str); + DBUG_RETURN(HA_ADMIN_INTERNAL_ERROR); + } + sql_print_information("View %`s.%`s: the version is set to %llu%s%s", + view->db.str, view->table_name.str, + view->mariadb_version, + (wrong_checksum ? ", checksum corrected" : ""), + (swap_alg ? + ((view->algorithm == VIEW_ALGORITHM_MERGE) ? + ", algorithm restored to be MERGE" + : ", algorithm restored to be TEMPTABLE") + : "")); + + + DBUG_RETURN(HA_ADMIN_OK); +} + + +/* + Register VIEW (write .frm & process .frm's history backups) + + SYNOPSIS + mysql_register_view() + thd - thread handler + view - view description + mode - VIEW_CREATE_NEW, VIEW_ALTER, VIEW_CREATE_OR_REPLACE + + RETURN + 0 OK + -1 Error + 1 Error and error message given +*/ + +static int mysql_register_view(THD *thd, TABLE_LIST *view, + enum_view_create_mode mode) +{ + LEX *lex= thd->lex; + + /* + Ensure character set number != 17 (character set = filename) and mbminlen=1 + because these character sets are not parser friendly, which can give weird + sequence in .frm file of view and later give parsing error. + */ + DBUG_ASSERT(thd->charset()->mbminlen == 1 && thd->charset()->number != 17); + + /* + View definition query -- a SELECT statement that fully defines view. It + is generated from the Item-tree built from the original (specified by + the user) query. The idea is that generated query should eliminates all + ambiguities and fix view structure at CREATE-time (once for all). + Item::print() virtual operation is used to generate view definition + query. + + INFORMATION_SCHEMA query (IS query) -- a SQL statement describing a + view that is shown in INFORMATION_SCHEMA. Basically, it is 'view + definition query' with text literals converted to UTF8 and without + character set introducers. + + For example: + Let's suppose we have: + CREATE TABLE t1(a INT, b INT); + User specified query: + CREATE VIEW v1(x, y) AS SELECT * FROM t1; + Generated query: + SELECT a AS x, b AS y FROM t1; + IS query: + SELECT a AS x, b AS y FROM t1; + + View definition query is stored in the client character set. + */ + StringBuffer<4096> view_query(thd->charset()); + StringBuffer<4096> is_query(system_charset_info); + + char md5[MD5_BUFF_LENGTH]; + bool can_be_merged; + char dir_buff[FN_REFLEN + 1], path_buff[FN_REFLEN + 1]; + LEX_CSTRING dir, file, path; + int error= 0; + DBUG_ENTER("mysql_register_view"); + + /* Generate view definition and IS queries. */ + view_query.length(0); + is_query.length(0); + { + Sql_mode_instant_remove sms(thd, MODE_ANSI_QUOTES); + + lex->unit.print(&view_query, enum_query_type(QT_VIEW_INTERNAL | + QT_ITEM_ORIGINAL_FUNC_NULLIF)); + lex->unit.print(&is_query, enum_query_type(QT_TO_SYSTEM_CHARSET | + QT_WITHOUT_INTRODUCERS | + QT_ITEM_ORIGINAL_FUNC_NULLIF)); + } + DBUG_PRINT("info", ("View: %.*s", view_query.length(), view_query.ptr())); + + /* fill structure */ + view->source= thd->lex->create_view->select; + + if (!thd->make_lex_string(&view->select_stmt, view_query.ptr(), + view_query.length())) + { + my_error(ER_OUT_OF_RESOURCES, MYF(0)); + error= -1; + goto err; + } + + /* + version 1 - before 10.0.5 + version 2 - empty definer_host means a role + */ + view->file_version= 2; + view->mariadb_version= MYSQL_VERSION_ID; + view->calc_md5(md5); + if (!(view->md5.str= (char*) thd->memdup(md5, 32))) + { + my_error(ER_OUT_OF_RESOURCES, MYF(0)); + error= -1; + goto err; + } + view->md5.length= 32; + can_be_merged= lex->can_be_merged(); + if (lex->create_view->algorithm == VIEW_ALGORITHM_MERGE && + !lex->can_be_merged()) + { + push_warning(thd, Sql_condition::WARN_LEVEL_WARN, ER_WARN_VIEW_MERGE, + ER_THD(thd, ER_WARN_VIEW_MERGE)); + lex->create_view->algorithm= DTYPE_ALGORITHM_UNDEFINED; + } + view->algorithm= lex->create_view->algorithm; + view->definer.user= lex->definer->user; + view->definer.host= lex->definer->host; + view->view_suid= lex->create_view->suid; + view->with_check= lex->create_view->check; + + DBUG_EXECUTE_IF("simulate_register_view_failure", + { + my_error(ER_OUT_OF_RESOURCES, MYF(0)); + error= -1; + goto err; + }); + + if ((view->updatable_view= (can_be_merged && + view->algorithm != VIEW_ALGORITHM_TMPTABLE))) + { + /* TODO: change here when we will support UNIONs */ + for (TABLE_LIST *tbl= lex->first_select_lex()->table_list.first; + tbl; + tbl= tbl->next_local) + { + if ((tbl->view && !tbl->updatable_view) || tbl->schema_table) + { + view->updatable_view= 0; + break; + } + for (TABLE_LIST *up= tbl; up; up= up->embedding) + { + if (up->outer_join) + { + view->updatable_view= 0; + goto loop_out; + } + } + } + } +loop_out: + /* print file name */ + make_view_filename(&dir, dir_buff, sizeof(dir_buff), + &path, path_buff, sizeof(path_buff), + &file, view); + /* init timestamp */ + if (!view->timestamp.str) + view->timestamp.str= view->timestamp_buffer; + + /* check old .frm */ + { + char path_buff[FN_REFLEN]; + LEX_CSTRING path; + File_parser *parser; + + path.str= path_buff; + fn_format(path_buff, file.str, dir.str, "", MY_UNPACK_FILENAME); + path.length= strlen(path_buff); + + if (ha_table_exists(thd, &view->db, &view->table_name)) + { + if (lex->create_info.if_not_exists()) + { + push_warning_printf(thd, Sql_condition::WARN_LEVEL_NOTE, + ER_TABLE_EXISTS_ERROR, + ER_THD(thd, ER_TABLE_EXISTS_ERROR), + view->table_name.str); + DBUG_RETURN(0); + } + else if (mode == VIEW_CREATE_NEW) + { + my_error(ER_TABLE_EXISTS_ERROR, MYF(0), view->alias.str); + error= -1; + goto err; + } + + if (!(parser= sql_parse_prepare(&path, thd->mem_root, 0))) + { + error= 1; + goto err; + } + + if (!parser->ok() || !is_equal(&view_type, parser->type())) + { + my_error(ER_WRONG_OBJECT, MYF(0), view->db.str, view->table_name.str, + "VIEW"); + error= -1; + goto err; + } + + /* + TODO: read dependence list, too, to process cascade/restrict + TODO: special cascade/restrict procedure for alter? + */ + } + else + { + if (mode == VIEW_ALTER) + { + my_error(ER_NO_SUCH_TABLE, MYF(0), view->db.str, view->alias.str); + error= -1; + goto err; + } + } + } + + /* Initialize view creation context from the environment. */ + + view->view_creation_ctx= View_creation_ctx::create(thd); + + /* + Set LEX_STRING attributes in view-structure for parser to create + frm-file. + */ + + lex_string_set(&view->view_client_cs_name, + view->view_creation_ctx->get_client_cs()->csname); + + lex_string_set(&view->view_connection_cl_name, + view->view_creation_ctx->get_connection_cl()->name); + + if (!thd->make_lex_string(&view->view_body_utf8, is_query.ptr(), + is_query.length())) + { + my_error(ER_OUT_OF_RESOURCES, MYF(0)); + error= -1; + goto err; + } + + /* + Check that table of main select do not used in subqueries. + + This test can catch only very simple cases of such non-updateable views, + all other will be detected before updating commands execution. + (it is more optimisation then real check) + + NOTE: this skip cases of using table via VIEWs, joined VIEWs, VIEWs with + UNION + */ + if (view->updatable_view && + !lex->first_select_lex()->master_unit()->is_unit_op() && + !(lex->first_select_lex()->table_list.first)->next_local && + find_table_in_global_list(lex->query_tables->next_global, + &lex->query_tables->db, + &lex->query_tables->table_name)) + { + view->updatable_view= 0; + } + + if (view->with_check != VIEW_CHECK_NONE && + !view->updatable_view) + { + my_error(ER_VIEW_NONUPD_CHECK, MYF(0), view->db.str, view->table_name.str); + error= -1; + goto err; + } + + if (sql_create_definition_file(&dir, &file, view_file_type, + (uchar*)view, view_parameters)) + { + error= thd->is_error() ? -1 : 1; + goto err; + } + DBUG_RETURN(0); +err: + view->select_stmt.str= NULL; + view->select_stmt.length= 0; + view->md5.str= NULL; + view->md5.length= 0; + DBUG_RETURN(error); +} + + + +/** + read VIEW .frm and create structures + + @param[in] thd Thread handler + @param[in] share Share object of view + @param[in] table TABLE_LIST structure for filling + @param[in] open_view_no_parse Flag to indicate open view but + do not parse. + + @return false-in case of success, true-in case of error. +*/ +bool mysql_make_view(THD *thd, TABLE_SHARE *share, TABLE_LIST *table, + bool open_view_no_parse) +{ + SELECT_LEX_NODE *end; + SELECT_LEX *UNINIT_VAR(view_select); + LEX *old_lex, *lex; + Query_arena *arena, backup; + TABLE_LIST *top_view= table->top_table(); + bool UNINIT_VAR(parse_status); + bool result, view_is_mergeable; + TABLE_LIST *UNINIT_VAR(view_main_select_tables); + DBUG_ENTER("mysql_make_view"); + DBUG_PRINT("info", ("table: %p (%s)", table, table->table_name.str)); + + if (table->required_type == TABLE_TYPE_NORMAL) + { + my_error(ER_WRONG_OBJECT, MYF(0), share->db.str, share->table_name.str, + "BASE TABLE"); + DBUG_RETURN(true); + } + + if (table->view) + { + /* + It's an execution of a PS/SP and the view has already been unfolded + into a list of used tables. Now we only need to update the information + about granted privileges in the view tables with the actual data + stored in MySQL privilege system. We don't need to restore the + required privileges (by calling register_want_access) because they has + not changed since PREPARE or the previous execution: the only case + when this information is changed is execution of UPDATE on a view, but + the original want_access is restored in its end. + */ + if (!table->prelocking_placeholder && table->prepare_security(thd)) + { + DBUG_RETURN(1); + } + DBUG_PRINT("info", + ("VIEW %s.%s is already processed on previous PS/SP execution", + table->view_db.str, table->view_name.str)); + + /* + Clear old variables in the TABLE_LIST that could be left from an old view + This is only needed if there was an error at last usage of view, + in which case the reinit call wasn't done. + See MDEV-6668 for details. + */ + mysql_handle_single_derived(thd->lex, table, DT_REINIT); + + DEBUG_SYNC(thd, "after_cached_view_opened"); + DBUG_RETURN(0); + } + + if (table->index_hints && table->index_hints->elements) + { + my_error(ER_KEY_DOES_NOT_EXISTS, MYF(0), + table->index_hints->head()->key_name.str, table->table_name.str); + DBUG_RETURN(TRUE); + } + + /* check loop via view definition */ + for (TABLE_LIST *precedent= table->referencing_view; + precedent; + precedent= precedent->referencing_view) + { + if (precedent->view_name.length == table->table_name.length && + precedent->view_db.length == table->db.length && + my_strcasecmp(system_charset_info, + precedent->view_name.str, table->table_name.str) == 0 && + my_strcasecmp(system_charset_info, + precedent->view_db.str, table->db.str) == 0) + { + my_error(ER_VIEW_RECURSIVE, MYF(0), + top_view->view_db.str, top_view->view_name.str); + DBUG_RETURN(TRUE); + } + } + + /* + For now we assume that tables will not be changed during PS life (it + will be TRUE as far as we make new table cache). + */ + old_lex= thd->lex; + arena= thd->activate_stmt_arena_if_needed(&backup); + + /* init timestamp */ + if (!table->timestamp.str) + table->timestamp.str= table->timestamp_buffer; + /* prepare default values for old format */ + table->view_suid= TRUE; + table->definer.user.str= table->definer.host.str= 0; + table->definer.user.length= table->definer.host.length= 0; + + /* + TODO: when VIEWs will be stored in cache (not only parser), + table mem_root should be used here + */ + DBUG_ASSERT(share->view_def != NULL); + if ((result= share->view_def->parse((uchar*)table, thd->mem_root, + view_parameters, + required_view_parameters, + &file_parser_dummy_hook))) + goto end; + + /* + check old format view .frm + */ + if (!table->definer.user.str) + { + DBUG_ASSERT(!table->definer.host.str && + !table->definer.user.length && + !table->definer.host.length); + push_warning_printf(thd, Sql_condition::WARN_LEVEL_WARN, + ER_VIEW_FRM_NO_USER, ER_THD(thd, ER_VIEW_FRM_NO_USER), + table->db.str, table->table_name.str); + get_default_definer(thd, &table->definer, false); + } + + /* + since 10.0.5 definer.host can never be "" for a User, but it's + always "" for a Role. Before 10.0.5 it could be "" for a User, + but roles didn't exist. file_version helps. + */ + if (!table->definer.host.str[0] && table->file_version < 2) + table->definer.host= host_not_specified; // User, not Role + + /* + Initialize view definition context by character set names loaded from + the view definition file. Use UTF8 character set if view definition + file is of old version and does not contain the character set names. + */ + table->view_creation_ctx= View_creation_ctx::create(thd, table); + + if (open_view_no_parse) + { + if (arena) + thd->restore_active_arena(arena, &backup); + DBUG_RETURN(FALSE); + } + + /* + Save VIEW parameters, which will be wiped out by derived table + processing + */ + table->view_db= table->db; + table->view_name= table->table_name; + /* + We don't invalidate a prepared statement when a view changes, + or when someone creates a temporary table. + Instead, the view is inlined into the body of the statement + upon the first execution. Below, make sure that on + re-execution of a prepared statement we don't prefer + a temporary table to the view, if the view name was shadowed + with a temporary table with the same name. + This assignment ensures that on re-execution open_table() will + not try to call find_temporary_table() for this TABLE_LIST, + but will invoke open_table_from_share(), which will + eventually call this function. + */ + table->open_type= OT_BASE_ONLY; + + /* + Clear old variables in the TABLE_LIST that could be left from an old view + */ + table->merged_for_insert= FALSE; + + /*TODO: md5 test here and warning if it is differ */ + + + /* + TODO: TABLE mem root should be used here when VIEW will be stored in + TABLE cache + + now Lex placed in statement memory + */ + + table->view= lex= thd->lex= (LEX*) new(thd->mem_root) st_lex_local; + if (!table->view) + { + result= true; + goto end; + } + + { + char old_db_buf[SAFE_NAME_LEN+1]; + LEX_CSTRING old_db= { old_db_buf, sizeof(old_db_buf) }; + bool dbchanged; + Parser_state parser_state; + if (parser_state.init(thd, table->select_stmt.str, + (uint)table->select_stmt.length)) + goto err; + + /* + Use view db name as thread default database, in order to ensure + that the view is parsed and prepared correctly. + */ + if ((result= mysql_opt_change_db(thd, &table->view_db, + (LEX_STRING*) &old_db, 1, + &dbchanged))) + goto end; + + lex_start(thd); + lex->stmt_lex= old_lex; + + sql_mode_t saved_mode= thd->variables.sql_mode; + /* switch off modes which can prevent normal parsing of VIEW + - MODE_REAL_AS_FLOAT affect only CREATE TABLE parsing + + MODE_PIPES_AS_CONCAT affect expression parsing + + MODE_ANSI_QUOTES affect expression parsing + + MODE_IGNORE_SPACE affect expression parsing + - MODE_IGNORE_BAD_TABLE_OPTIONS affect only CREATE/ALTER TABLE parsing + * MODE_ONLY_FULL_GROUP_BY affect execution + * MODE_NO_UNSIGNED_SUBTRACTION affect execution + - MODE_NO_DIR_IN_CREATE affect table creation only + - MODE_POSTGRESQL compounded from other modes + - MODE_ORACLE affects Item creation (e.g for CONCAT) + - MODE_MSSQL compounded from other modes + - MODE_DB2 compounded from other modes + - MODE_MAXDB affect only CREATE TABLE parsing + - MODE_NO_KEY_OPTIONS affect only SHOW + - MODE_NO_TABLE_OPTIONS affect only SHOW + - MODE_NO_FIELD_OPTIONS affect only SHOW + - MODE_MYSQL323 affect only SHOW + - MODE_MYSQL40 affect only SHOW + - MODE_ANSI compounded from other modes + (+ transaction mode) + ? MODE_NO_AUTO_VALUE_ON_ZERO affect UPDATEs + + MODE_NO_BACKSLASH_ESCAPES affect expression parsing + */ + thd->variables.sql_mode&= ~(MODE_PIPES_AS_CONCAT | MODE_ANSI_QUOTES | + MODE_IGNORE_SPACE | MODE_NO_BACKSLASH_ESCAPES | + MODE_ORACLE); + + /* Parse the query. */ + + parse_status= parse_sql(thd, & parser_state, table->view_creation_ctx); + + view_select= lex->first_select_lex(); + + /* Restore environment. */ + + if ((old_lex->sql_command == SQLCOM_SHOW_FIELDS) || + (old_lex->sql_command == SQLCOM_SHOW_CREATE)) + lex->sql_command= old_lex->sql_command; + + thd->variables.sql_mode= saved_mode; + + if (dbchanged && mysql_change_db(thd, &old_db, TRUE)) + goto err; + } + if (!parse_status) + { + TABLE_LIST *view_tables= lex->query_tables; + TABLE_LIST *view_tables_tail= 0; + TABLE_LIST *tbl; + Security_context *security_ctx= 0; + + /* + Check rights to run commands which show underlying tables. + In the optimizer trace we would not like to show trace for + cases when the current user does not have rights for the + underlying tables. + */ + if (!table->prelocking_placeholder) + opt_trace_disable_if_no_view_access(thd, table, view_tables); + + /* + Check rights to run commands (ANALYZE SELECT, EXPLAIN SELECT & + SHOW CREATE) which show underlying tables. + Skip this step if we are opening view for prelocking only. + */ + if (!table->prelocking_placeholder && (old_lex->describe || + old_lex->analyze_stmt)) + { + /* + The user we run EXPLAIN as (either the connected user who issued + the EXPLAIN statement, or the definer of a SUID stored routine + which contains the EXPLAIN) should have both SHOW_VIEW_ACL and + SELECT_ACL on the view being opened as well as on all underlying + views since EXPLAIN will disclose their structure. This user also + should have SELECT_ACL on all underlying tables of the view since + this EXPLAIN will disclose information about the number of rows in it. + + To perform this privilege check we create auxiliary TABLE_LIST object + for the view in order a) to avoid trashing "table->grant" member for + original table list element, which contents can be important at later + stage for column-level privilege checking b) get TABLE_LIST object + with "security_ctx" member set to 0, i.e. forcing check_table_access() + to use active user's security context. + + There is no need for creating similar copies of TABLE_LIST elements + for underlying tables since they just have been constructed and thus + have TABLE_LIST::security_ctx == 0 and fresh TABLE_LIST::grant member. + + Finally at this point making sure we have SHOW_VIEW_ACL on the views + will suffice as we implicitly require SELECT_ACL anyway. + */ + + TABLE_LIST view_no_suid; + bzero(static_cast<void *>(&view_no_suid), sizeof(TABLE_LIST)); + view_no_suid.db= table->db; + view_no_suid.table_name= table->table_name; + + DBUG_ASSERT(view_tables == NULL || view_tables->security_ctx == NULL); + + if (check_table_access(thd, SELECT_ACL, view_tables, + FALSE, UINT_MAX, TRUE) || + check_table_access(thd, SHOW_VIEW_ACL, &view_no_suid, + FALSE, UINT_MAX, TRUE)) + { + my_message(ER_VIEW_NO_EXPLAIN, ER_THD(thd, ER_VIEW_NO_EXPLAIN), + MYF(0)); + goto err; + } + } + else if (!table->prelocking_placeholder && + (old_lex->sql_command == SQLCOM_SHOW_CREATE) && + !table->belong_to_view) + { + if (check_table_access(thd, SHOW_VIEW_ACL, table, FALSE, UINT_MAX, FALSE)) + goto err; + } + + if (!(table->view_tables= + (List<TABLE_LIST>*) new(thd->mem_root) List<TABLE_LIST>)) + goto err; + /* + mark to avoid temporary table using and put view reference and find + last view table + */ + for (tbl= view_tables; + tbl; + tbl= (view_tables_tail= tbl)->next_global) + { + tbl->open_type= OT_BASE_ONLY; + tbl->belong_to_view= top_view; + tbl->referencing_view= table; + tbl->prelocking_placeholder= table->prelocking_placeholder; + /* + First we fill want_privilege with SELECT_ACL (this is needed for the + tables which belongs to view subqueries and temporary table views, + then for the merged view underlying tables we will set wanted + privileges of top_view + */ + tbl->grant.want_privilege= SELECT_ACL; + + /* + After unfolding the view we lose the list of tables referenced in it + (we will have only a list of underlying tables in case of MERGE + algorithm, which does not include the tables referenced from + subqueries used in view definition). + Let's build a list of all tables referenced in the view. + */ + table->view_tables->push_back(tbl); + } + + /* + Put tables of VIEW after VIEW TABLE_LIST + + NOTE: It is important for UPDATE/INSERT/DELETE checks to have this + tables just after VIEW instead of tail of list, to be able check that + table is unique. Also we store old next table for the same purpose. + */ + if (view_tables) + { + if (table->next_global) + { + view_tables_tail->next_global= table->next_global; + table->next_global->prev_global= &view_tables_tail->next_global; + } + else + { + old_lex->query_tables_last= &view_tables_tail->next_global; + } + view_tables->prev_global= &table->next_global; + table->next_global= view_tables; + } + + /* + If the view's body needs row-based binlogging (e.g. the VIEW is created + from SELECT UUID()), the top statement also needs it. + */ + old_lex->set_stmt_unsafe_flags(lex->get_stmt_unsafe_flags()); + + view_is_mergeable= (table->algorithm != VIEW_ALGORITHM_TMPTABLE && + lex->can_be_merged()); + + if (view_is_mergeable) + { + /* + Currently 'view_main_select_tables' differs from 'view_tables' + only then view has CONVERT_TZ() function in its select list. + This may change in future, for example if we enable merging of + views with subqueries in select list. + */ + view_main_select_tables= lex->first_select_lex()->table_list.first; + /* + Mergeable view can be used for inserting, so we move the flag down + */ + if (table->for_insert_data) + { + for (TABLE_LIST *t= view_main_select_tables; + t; + t= t->next_local) + { + t->for_insert_data= TRUE; + } + } + + /* + Let us set proper lock type for tables of the view's main + select since we may want to perform update or insert on + view. This won't work for view containing union. But this is + ok since we don't allow insert and update on such views + anyway. + */ + for (tbl= view_main_select_tables; tbl; tbl= tbl->next_local) + { + /* We have to keep the lock type for sequence tables */ + if (!tbl->sequence) + tbl->lock_type= table->lock_type; + tbl->mdl_request.set_type(table->mdl_request.type); + tbl->updating= table->updating; + } + /* + If the view is mergeable, we might want to + INSERT/UPDATE/DELETE into tables of this view. Preserve the + original sql command and 'duplicates' of the outer lex. + This is used later in set_trg_event_type_for_command. + */ + lex->sql_command= old_lex->sql_command; + lex->duplicates= old_lex->duplicates; + + /* Fields in this view can be used in upper select in case of merge. */ + if (table->select_lex) + table->select_lex->add_where_field(lex->first_select_lex()); + } + /* + This method has a dependency on the proper lock type being set, + so in case of views should be called here. + */ + lex->set_trg_event_type_for_tables(); + + /* + If we are opening this view as part of implicit LOCK TABLES, then + this view serves as simple placeholder and we should not continue + further processing. + */ + if (table->prelocking_placeholder) + goto ok2; + + old_lex->derived_tables|= (DERIVED_VIEW | lex->derived_tables); + + /* move SQL_NO_CACHE & Co to whole query */ + old_lex->safe_to_cache_query= (old_lex->safe_to_cache_query && + lex->safe_to_cache_query); + /* move SQL_CACHE to whole query */ + if (lex->first_select_lex()->options & OPTION_TO_QUERY_CACHE) + old_lex->first_select_lex()->options|= OPTION_TO_QUERY_CACHE; + +#ifndef NO_EMBEDDED_ACCESS_CHECKS + if (table->view_suid) + { + /* + For suid views prepare a security context for checking underlying + objects of the view. + */ + if (!(table->view_sctx= (Security_context *) + thd->stmt_arena->calloc(sizeof(Security_context)))) + goto err; + security_ctx= table->view_sctx; + } + else + { + /* + For non-suid views inherit security context from view's table list. + This allows properly handle situation when non-suid view is used + from within suid view. + */ + security_ctx= table->security_ctx; + } +#endif + + /* Assign the context to the tables referenced in the view */ + if (view_tables) + { + DBUG_ASSERT(view_tables_tail); + for (tbl= view_tables; tbl != view_tables_tail->next_global; + tbl= tbl->next_global) + tbl->security_ctx= security_ctx; + } + + /* assign security context to SELECT name resolution contexts of view */ + for(SELECT_LEX *sl= lex->all_selects_list; + sl; + sl= sl->next_select_in_list()) + sl->context.security_ctx= security_ctx; + + /* + Setup an error processor to hide error messages issued by stored + routines referenced in the view + */ + for (SELECT_LEX *sl= lex->all_selects_list; + sl; + sl= sl->next_select_in_list()) + { + sl->context.error_processor= &view_error_processor; + sl->context.error_processor_data= (void *)table; + } + + view_select->master_unit()->is_view= true; + + /* + check MERGE algorithm ability + - algorithm is not explicit TEMPORARY TABLE + - VIEW SELECT allow merging + - VIEW used in subquery or command support MERGE algorithm + */ + if (view_is_mergeable && + (table->select_lex->master_unit() != &old_lex->unit || + old_lex->can_use_merged()) && + !old_lex->can_not_use_merged()) + { + /* lex should contain at least one table */ + DBUG_ASSERT(view_main_select_tables != 0); + + List_iterator_fast<TABLE_LIST> ti(view_select->top_join_list); + + table->derived_type= VIEW_ALGORITHM_MERGE; + DBUG_PRINT("info", ("algorithm: MERGE")); + table->updatable= (table->updatable_view != 0); + table->effective_with_check= + old_lex->get_effective_with_check(table); + table->merge_underlying_list= view_main_select_tables; + + /* Fill correct wanted privileges. */ + for (tbl= view_main_select_tables; tbl; tbl= tbl->next_local) + tbl->grant.want_privilege= top_view->grant.orig_want_privilege; + + /* prepare view context */ + lex->first_select_lex()-> + context.resolve_in_table_list_only(view_main_select_tables); + lex->first_select_lex()->context.outer_context= 0; + lex->first_select_lex()->select_n_having_items+= + table->select_lex->select_n_having_items; + + table->where= view_select->where; + + /* + We can safely ignore the VIEW's ORDER BY if we merge into union + branch, as order is not important there. + */ + if (!table->select_lex->master_unit()->is_unit_op() && + table->select_lex->order_list.elements == 0) + table->select_lex->order_list. + push_back(&lex->first_select_lex()->order_list); + else + { + if (old_lex->sql_command == SQLCOM_SELECT && + (old_lex->describe & DESCRIBE_EXTENDED) && + lex->first_select_lex()->order_list.elements && + !table->select_lex->master_unit()->is_unit_op()) + { + push_warning_printf(thd, Sql_condition::WARN_LEVEL_NOTE, + ER_VIEW_ORDERBY_IGNORED, + ER_THD(thd, ER_VIEW_ORDERBY_IGNORED), + table->db.str, table->table_name.str); + } + } + /* + This SELECT_LEX will be linked in global SELECT_LEX list + to make it processed by mysql_handle_derived(), + but it will not be included to SELECT_LEX tree, because it + will not be executed + */ + goto ok; + } + + table->derived_type= VIEW_ALGORITHM_TMPTABLE; + DBUG_PRINT("info", ("algorithm: TEMPORARY TABLE")); + view_select->linkage= DERIVED_TABLE_TYPE; + table->updatable= 0; + table->effective_with_check= VIEW_CHECK_NONE; + + table->derived= &lex->unit; + } + else + goto err; + +ok: + /* SELECT tree link */ + lex->unit.include_down(table->select_lex); + lex->unit.slave= view_select; // fix include_down initialisation + /* global SELECT list linking */ + /* + The primary SELECT_LEX is always last (because parsed first) if WITH not + used, otherwise it is good start point for last element finding + */ + for (end= view_select; end->link_next; end= end->link_next); + end->link_next= old_lex->all_selects_list; + old_lex->all_selects_list->link_prev= &end->link_next; + old_lex->all_selects_list= lex->all_selects_list; + lex->all_selects_list->link_prev= + (st_select_lex_node**)&old_lex->all_selects_list; + +ok2: + DBUG_ASSERT(lex == thd->lex); + thd->lex= old_lex; // Needed for prepare_security + result= !table->prelocking_placeholder && table->prepare_security(thd); + + lex_end(lex); +end: + if (arena) + thd->restore_active_arena(arena, &backup); + thd->lex= old_lex; + status_var_increment(thd->status_var.opened_views); + DBUG_RETURN(result); + +err: + DBUG_ASSERT(thd->lex == table->view); + lex_end(thd->lex); + delete table->view; + table->view= 0; // now it is not VIEW placeholder + result= 1; + goto end; +} + + +/* + drop view + + SYNOPSIS + mysql_drop_view() + thd - thread handle + views - views to delete + drop_mode - cascade/check + + RETURN VALUE + FALSE OK + TRUE Error +*/ + +bool mysql_drop_view(THD *thd, TABLE_LIST *views, enum_drop_mode drop_mode) +{ + char path[FN_REFLEN + 1]; + TABLE_LIST *view; + String non_existant_views; + bool delete_error= FALSE, wrong_object_name= FALSE; + bool some_views_deleted= FALSE; + bool something_wrong= FALSE; + uint not_exists_count= 0; + DBUG_ENTER("mysql_drop_view"); + + /* + We can't allow dropping of unlocked view under LOCK TABLES since this + might lead to deadlock. But since we can't really lock view with LOCK + TABLES we have to simply prohibit dropping of views. + */ + + if (unlikely(thd->locked_tables_mode)) + { + my_error(ER_LOCK_OR_ACTIVE_TRANSACTION, MYF(0)); + DBUG_RETURN(TRUE); + } + + if (unlikely(lock_table_names(thd, views, 0, + thd->variables.lock_wait_timeout, 0))) + DBUG_RETURN(TRUE); + + for (view= views; view; view= view->next_local) + { + bool not_exist; + build_table_filename(path, sizeof(path) - 1, + view->db.str, view->table_name.str, reg_ext, 0); + + if ((not_exist= my_access(path, F_OK)) || !dd_frm_is_view(thd, path)) + { + char name[FN_REFLEN]; + my_snprintf(name, sizeof(name), "%s.%s", view->db.str, + view->table_name.str); + if (non_existant_views.length()) + non_existant_views.append(','); + non_existant_views.append(name); + + if (!not_exist) + { + wrong_object_name= 1; + my_error(ER_WRONG_OBJECT, MYF(ME_WARNING), view->db.str, + view->table_name.str, "VIEW"); + } + else + not_exists_count++; + continue; + } + if (unlikely(mysql_file_delete(key_file_frm, path, MYF(MY_WME)))) + delete_error= TRUE; + + some_views_deleted= TRUE; + + /* + For a view, there is a TABLE_SHARE object. + Remove it from the table definition cache, in case the view was cached. + */ + tdc_remove_table(thd, view->db.str, view->table_name.str); + query_cache_invalidate3(thd, view, 0); + sp_cache_invalidate(); + } + + something_wrong= (delete_error || + (!thd->lex->if_exists() && (not_exists_count || + wrong_object_name))); + + if (unlikely(non_existant_views.length())) + { + my_error(ER_UNKNOWN_VIEW, MYF(something_wrong ? 0 : ME_NOTE), + non_existant_views.c_ptr_safe()); + } + + if (some_views_deleted || !something_wrong) + { + /* if something goes wrong, bin-log with possible error code, + otherwise bin-log with error code cleared. + */ + if (unlikely(write_bin_log(thd, !something_wrong, thd->query(), + thd->query_length()))) + something_wrong= 1; + } + + if (unlikely(something_wrong)) + { + DBUG_RETURN(TRUE); + } + my_ok(thd); + DBUG_RETURN(FALSE); +} + + +/* + check of key (primary or unique) presence in updatable view + + SYNOPSIS + check_key_in_view() + thd thread handle + view view for check with opened table + + DESCRIPTION + If it is VIEW and query have LIMIT clause then check that underlying + table of view contain one of following: + 1) primary key of underlying table + 2) unique key underlying table with fields for which NULL value is + impossible + 3) all fields of underlying table + + RETURN + FALSE OK + TRUE view do not contain key or all fields +*/ + +bool check_key_in_view(THD *thd, TABLE_LIST *view) +{ + TABLE *table; + Field_translator *trans, *end_of_trans; + KEY *key_info, *key_info_end; + DBUG_ENTER("check_key_in_view"); + + /* + we do not support updatable UNIONs in VIEW, so we can check just limit of + LEX::select_lex + */ + if ((!view->view && !view->belong_to_view) || + thd->lex->sql_command == SQLCOM_INSERT || + thd->lex->first_select_lex()->select_limit == 0) + DBUG_RETURN(FALSE); /* it is normal table or query without LIMIT */ + table= view->table; + view= view->top_table(); + trans= view->field_translation; + key_info_end= (key_info= table->key_info)+ table->s->keys; + + end_of_trans= view->field_translation_end; + DBUG_ASSERT(table != 0 && view->field_translation != 0); + + { + /* + We should be sure that all fields are ready to get keys from them, but + this operation should not have influence on Field::query_id, to avoid + marking as used fields which are not used + */ + enum_column_usage saved_column_usage= thd->column_usage; + thd->column_usage= COLUMNS_WRITE; + DBUG_PRINT("info", ("thd->column_usage: %d", thd->column_usage)); + for (Field_translator *fld= trans; fld < end_of_trans; fld++) + { + if (fld->item->fix_fields_if_needed(thd, &fld->item)) + { + thd->column_usage= saved_column_usage; + DBUG_RETURN(TRUE); + } + } + thd->column_usage= saved_column_usage; + DBUG_PRINT("info", ("thd->column_usage: %d", thd->column_usage)); + } + /* Loop over all keys to see if a unique-not-null key is used */ + for (;key_info != key_info_end ; key_info++) + { + if ((key_info->flags & (HA_NOSAME | HA_NULL_PART_KEY)) == HA_NOSAME) + { + KEY_PART_INFO *key_part= key_info->key_part; + KEY_PART_INFO *key_part_end= key_part + key_info->user_defined_key_parts; + + /* check that all key parts are used */ + for (;;) + { + Field_translator *k; + for (k= trans; k < end_of_trans; k++) + { + Item_field *field; + if ((field= k->item->field_for_view_update()) && + field->field == key_part->field) + break; + } + if (k == end_of_trans) + break; // Key is not possible + if (++key_part == key_part_end) + DBUG_RETURN(FALSE); // Found usable key + } + } + } + + DBUG_PRINT("info", ("checking if all fields of table are used")); + /* check all fields presence */ + { + Field **field_ptr; + Field_translator *fld; + for (field_ptr= table->field; *field_ptr; field_ptr++) + { + for (fld= trans; fld < end_of_trans; fld++) + { + Item_field *field; + if ((field= fld->item->field_for_view_update()) && + field->field == *field_ptr) + break; + } + if (fld == end_of_trans) // If field didn't exists + { + /* + Keys or all fields of underlying tables are not found => we have + to check variable updatable_views_with_limit to decide should we + issue an error or just a warning + */ + if (thd->variables.updatable_views_with_limit) + { + /* update allowed, but issue warning */ + push_warning(thd, Sql_condition::WARN_LEVEL_NOTE, + ER_WARN_VIEW_WITHOUT_KEY, + ER_THD(thd, ER_WARN_VIEW_WITHOUT_KEY)); + DBUG_RETURN(FALSE); + } + /* prohibit update */ + DBUG_RETURN(TRUE); + } + } + } + DBUG_RETURN(FALSE); +} + + +/* + insert fields from VIEW (MERGE algorithm) into given list + + SYNOPSIS + insert_view_fields() + thd thread handler + list list for insertion + view view for processing + + RETURN + FALSE OK + TRUE error (is not sent to client) +*/ + +bool insert_view_fields(THD *thd, List<Item> *list, TABLE_LIST *view) +{ + Field_translator *trans_end; + Field_translator *trans; + DBUG_ENTER("insert_view_fields"); + + if (!(trans= view->field_translation)) + DBUG_RETURN(FALSE); + trans_end= view->field_translation_end; + + for (Field_translator *entry= trans; entry < trans_end; entry++) + { + Item_field *fld; + if ((fld= entry->item->field_for_view_update())) + { + TABLE_SHARE *s= fld->context->table_list->table->s; + Lex_ident field_name= fld->field_name; + if (s->versioned && + (field_name.streq(s->vers_start_field()->field_name) || + field_name.streq(s->vers_end_field()->field_name))) + continue; + list->push_back(fld, thd->mem_root); + } + else + { + my_error(ER_NON_INSERTABLE_TABLE, MYF(0), view->alias.str, "INSERT"); + DBUG_RETURN(TRUE); + } + } + DBUG_RETURN(FALSE); +} + +/* + checking view md5 check sum + + SINOPSYS + view_checksum() + thd threar handler + view view for check + + RETUIRN + HA_ADMIN_OK OK + HA_ADMIN_NOT_IMPLEMENTED it is not VIEW + HA_ADMIN_WRONG_CHECKSUM check sum is wrong +*/ + +int view_checksum(THD *thd, TABLE_LIST *view) +{ + char md5[MD5_BUFF_LENGTH]; + if (!view->view || view->md5.length != 32) + return HA_ADMIN_NOT_IMPLEMENTED; + view->calc_md5(md5); + return (strncmp(md5, view->md5.str, 32) ? + HA_ADMIN_WRONG_CHECKSUM : + HA_ADMIN_OK); +} + +/** + Check view + + @param thd thread handle + @param view view for check + @param check_opt check options + + @retval HA_ADMIN_OK OK + @retval HA_ADMIN_NOT_IMPLEMENTED it is not VIEW + @retval HA_ADMIN_WRONG_CHECKSUM check sum is wrong +*/ +int view_check(THD *thd, TABLE_LIST *view, HA_CHECK_OPT *check_opt) +{ + DBUG_ENTER("view_check"); + + int res= view_checksum(thd, view); + if (res != HA_ADMIN_OK) + DBUG_RETURN(res); + + if (((check_opt->sql_flags & TT_FOR_UPGRADE) && !view->mariadb_version)) + DBUG_RETURN(HA_ADMIN_NEEDS_UPGRADE); + + DBUG_RETURN(HA_ADMIN_OK); +} + + +/** + Repair view + + @param thd thread handle + @param view view for check + @param check_opt check options + + @retval HA_ADMIN_OK OK + @retval HA_ADMIN_NOT_IMPLEMENTED it is not VIEW + @retval HA_ADMIN_WRONG_CHECKSUM check sum is wrong +*/ + +int view_repair(THD *thd, TABLE_LIST *view, HA_CHECK_OPT *check_opt) +{ + DBUG_ENTER("view_repair"); + bool swap_alg= (check_opt->sql_flags & TT_FROM_MYSQL); + bool wrong_checksum= view_checksum(thd, view) != HA_ADMIN_OK; + int ret; + if (wrong_checksum || swap_alg || (!view->mariadb_version)) + { + ret= mariadb_fix_view(thd, view, wrong_checksum, swap_alg); + DBUG_RETURN(ret); + } + DBUG_RETURN(HA_ADMIN_OK); +} + +/* + rename view + + Synopsis: + renames a view + + Parameters: + thd thread handler + new_db new name of database + new_name new name of view + view view + + Return values: + FALSE Ok + TRUE Error +*/ +bool +mysql_rename_view(THD *thd, + const LEX_CSTRING *new_db, + const LEX_CSTRING *new_name, + TABLE_LIST *view) +{ + LEX_CSTRING pathstr; + File_parser *parser; + char path_buff[FN_REFLEN + 1]; + bool error= TRUE; + DBUG_ENTER("mysql_rename_view"); + + pathstr.str= (char *) path_buff; + pathstr.length= build_table_filename(path_buff, sizeof(path_buff) - 1, + view->db.str, view->table_name.str, + reg_ext, 0); + + if ((parser= sql_parse_prepare(&pathstr, thd->mem_root, 1)) && + is_equal(&view_type, parser->type())) + { + TABLE_LIST view_def; + char dir_buff[FN_REFLEN + 1]; + LEX_CSTRING dir, file; + + /* + To be PS-friendly we should either to restore state of + TABLE_LIST object pointed by 'view' after using it for + view definition parsing or use temporary 'view_def' + object for it. + */ + view_def.reset(); + view_def.timestamp.str= view_def.timestamp_buffer; + view_def.view_suid= TRUE; + + /* get view definition and source */ + if (parser->parse((uchar*)&view_def, thd->mem_root, view_parameters, + array_elements(view_parameters)-1, + &file_parser_dummy_hook)) + goto err; + + /* rename view and it's backups */ + if (rename_in_schema_file(thd, view->db.str, view->table_name.str, + new_db->str, new_name->str)) + goto err; + + dir.str= dir_buff; + dir.length= build_table_filename(dir_buff, sizeof(dir_buff) - 1, + new_db->str, "", "", 0); + + pathstr.str= path_buff; + pathstr.length= build_table_filename(path_buff, sizeof(path_buff) - 1, + new_db->str, new_name->str, reg_ext, 0); + + file.str= pathstr.str + dir.length; + file.length= pathstr.length - dir.length; + + if (sql_create_definition_file(&dir, &file, view_file_type, + (uchar*)&view_def, view_parameters)) + { + /* restore renamed view in case of error */ + rename_in_schema_file(thd, new_db->str, new_name->str, view->db.str, + view->table_name.str); + goto err; + } + } else + DBUG_RETURN(1); + + /* remove cache entries */ + query_cache_invalidate3(thd, view, 0); + sp_cache_invalidate(); + error= FALSE; + +err: + DBUG_RETURN(error); +} |