diff options
Diffstat (limited to 'sql/sql_update.cc')
| -rw-r--r-- | sql/sql_update.cc | 3100 |
1 files changed, 3100 insertions, 0 deletions
diff --git a/sql/sql_update.cc b/sql/sql_update.cc new file mode 100644 index 00000000..977e459f --- /dev/null +++ b/sql/sql_update.cc @@ -0,0 +1,3100 @@ +/* Copyright (c) 2000, 2016, Oracle and/or its affiliates. + Copyright (c) 2011, 2021, MariaDB + + 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 St, Fifth Floor, Boston, MA 02110-1335 USA */ + + +/* + Single table and multi table updates of tables. + Multi-table updates were introduced by Sinisa & Monty +*/ + +#include "mariadb.h" /* NO_EMBEDDED_ACCESS_CHECKS */ +#include "sql_priv.h" +#include "sql_update.h" +#include "sql_cache.h" // query_cache_* +#include "sql_base.h" // close_tables_for_reopen +#include "sql_parse.h" // cleanup_items +#include "sql_partition.h" // partition_key_modified +#include "sql_select.h" +#include "sql_view.h" // check_key_in_view +#include "sp_head.h" +#include "sql_trigger.h" +#include "sql_statistics.h" +#include "probes_mysql.h" +#include "debug_sync.h" +#include "key.h" // is_key_used +#include "records.h" // init_read_record, + // end_read_record +#include "filesort.h" // filesort +#include "sql_derived.h" // mysql_derived_prepare, + // mysql_handle_derived, + // mysql_derived_filling + + +#include "sql_insert.h" // For vers_insert_history_row() that may be + // needed for System Versioning. + +/** + True if the table's input and output record buffers are comparable using + compare_record(TABLE*). + */ +bool records_are_comparable(const TABLE *table) { + return !table->versioned(VERS_TRX_ID) && + (((table->file->ha_table_flags() & HA_PARTIAL_COLUMN_READ) == 0) || + bitmap_is_subset(table->write_set, table->read_set)); +} + + +/** + Compares the input and outbut record buffers of the table to see if a row + has changed. + + @return true if row has changed. + @return false otherwise. +*/ + +bool compare_record(const TABLE *table) +{ + DBUG_ASSERT(records_are_comparable(table)); + + if (table->file->ha_table_flags() & HA_PARTIAL_COLUMN_READ || + table->s->has_update_default_function) + { + /* + Storage engine may not have read all columns of the record. Fields + (including NULL bits) not in the write_set may not have been read and + can therefore not be compared. + Or ON UPDATE DEFAULT NOW() could've changed field values, including + NULL bits. + */ + for (Field **ptr= table->field ; *ptr != NULL; ptr++) + { + Field *field= *ptr; + if (field->has_explicit_value() && !field->vcol_info) + { + if (field->real_maybe_null()) + { + uchar null_byte_index= (uchar)(field->null_ptr - table->record[0]); + + if (((table->record[0][null_byte_index]) & field->null_bit) != + ((table->record[1][null_byte_index]) & field->null_bit)) + return TRUE; + } + if (field->cmp_binary_offset(table->s->rec_buff_length)) + return TRUE; + } + } + return FALSE; + } + + /* + The storage engine has read all columns, so it's safe to compare all bits + including those not in the write_set. This is cheaper than the + field-by-field comparison done above. + */ + if (table->s->can_cmp_whole_record) + return cmp_record(table,record[1]); + /* Compare null bits */ + if (memcmp(table->null_flags, + table->null_flags+table->s->rec_buff_length, + table->s->null_bytes_for_compare)) + return TRUE; // Diff in NULL value + /* Compare updated fields */ + for (Field **ptr= table->field ; *ptr ; ptr++) + { + Field *field= *ptr; + if (field->has_explicit_value() && !field->vcol_info && + field->cmp_binary_offset(table->s->rec_buff_length)) + return TRUE; + } + return FALSE; +} + + +/* + check that all fields are real fields + + SYNOPSIS + check_fields() + thd thread handler + items Items for check + + RETURN + TRUE Items can't be used in UPDATE + FALSE Items are OK +*/ + +static bool check_fields(THD *thd, TABLE_LIST *table, List<Item> &items, + bool update_view) +{ + Item *item; + if (update_view) + { + List_iterator<Item> it(items); + Item_field *field; + while ((item= it++)) + { + if (!(field= item->field_for_view_update())) + { + /* item has name, because it comes from VIEW SELECT list */ + my_error(ER_NONUPDATEABLE_COLUMN, MYF(0), item->name.str); + return TRUE; + } + /* + we make temporary copy of Item_field, to avoid influence of changing + result_field on Item_ref which refer on this field + */ + thd->change_item_tree(it.ref(), + new (thd->mem_root) Item_field(thd, field)); + } + } + + if (thd->variables.sql_mode & MODE_SIMULTANEOUS_ASSIGNMENT) + { + // Make sure that a column is updated only once + List_iterator_fast<Item> it(items); + while ((item= it++)) + { + item->field_for_view_update()->field->clear_has_explicit_value(); + } + it.rewind(); + while ((item= it++)) + { + Field *f= item->field_for_view_update()->field; + if (f->has_explicit_value()) + { + my_error(ER_UPDATED_COLUMN_ONLY_ONCE, MYF(0), + *(f->table_name), f->field_name.str); + return TRUE; + } + f->set_has_explicit_value(); + } + } + + if (table->has_period()) + { + if (table->is_view_or_derived()) + { + my_error(ER_IT_IS_A_VIEW, MYF(0), table->table_name.str); + return TRUE; + } + if (thd->lex->sql_command == SQLCOM_UPDATE_MULTI) + { + my_error(ER_NOT_SUPPORTED_YET, MYF(0), + "updating and querying the same temporal periods table"); + + return true; + } + DBUG_ASSERT(thd->lex->sql_command == SQLCOM_UPDATE); + for (List_iterator_fast<Item> it(items); (item=it++);) + { + Field *f= item->field_for_view_update()->field; + vers_select_conds_t &period= table->period_conditions; + if (period.field_start->field == f || period.field_end->field == f) + { + my_error(ER_PERIOD_COLUMNS_UPDATED, MYF(0), + item->name.str, period.name.str); + return true; + } + } + } + return FALSE; +} + +bool TABLE::vers_check_update(List<Item> &items) +{ + List_iterator<Item> it(items); + if (!versioned_write()) + return false; + + while (Item *item= it++) + { + if (Item_field *item_field= item->field_for_view_update()) + { + Field *field= item_field->field; + if (field->table == this && !field->vers_update_unversioned()) + { + no_cache= true; + return true; + } + } + } + return false; +} + +/** + Re-read record if more columns are needed for error message. + + If we got a duplicate key error, we want to write an error + message containing the value of the duplicate key. If we do not have + all fields of the key value in record[0], we need to re-read the + record with a proper read_set. + + @param[in] error error number + @param[in] table table +*/ + +static void prepare_record_for_error_message(int error, TABLE *table) +{ + Field **field_p; + Field *field; + uint keynr; + MY_BITMAP unique_map; /* Fields in offended unique. */ + my_bitmap_map unique_map_buf[bitmap_buffer_size(MAX_FIELDS)]; + DBUG_ENTER("prepare_record_for_error_message"); + + /* + Only duplicate key errors print the key value. + If storage engine does always read all columns, we have the value alraedy. + */ + if ((error != HA_ERR_FOUND_DUPP_KEY) || + !(table->file->ha_table_flags() & HA_PARTIAL_COLUMN_READ)) + DBUG_VOID_RETURN; + + /* + Get the number of the offended index. + We will see MAX_KEY if the engine cannot determine the affected index. + */ + if (unlikely((keynr= table->file->get_dup_key(error)) >= MAX_KEY)) + DBUG_VOID_RETURN; + + /* Create unique_map with all fields used by that index. */ + my_bitmap_init(&unique_map, unique_map_buf, table->s->fields, FALSE); + table->mark_index_columns(keynr, &unique_map); + + /* Subtract read_set and write_set. */ + bitmap_subtract(&unique_map, table->read_set); + bitmap_subtract(&unique_map, table->write_set); + + /* + If the unique index uses columns that are neither in read_set + nor in write_set, we must re-read the record. + Otherwise no need to do anything. + */ + if (bitmap_is_clear_all(&unique_map)) + DBUG_VOID_RETURN; + + /* Get identifier of last read record into table->file->ref. */ + table->file->position(table->record[0]); + /* Add all fields used by unique index to read_set. */ + bitmap_union(table->read_set, &unique_map); + /* Tell the engine about the new set. */ + table->file->column_bitmaps_signal(); + + if ((error= table->file->ha_index_or_rnd_end()) || + (error= table->file->ha_rnd_init(0))) + { + table->file->print_error(error, MYF(0)); + DBUG_VOID_RETURN; + } + + /* Read record that is identified by table->file->ref. */ + (void) table->file->ha_rnd_pos(table->record[1], table->file->ref); + /* Copy the newly read columns into the new record. */ + for (field_p= table->field; (field= *field_p); field_p++) + if (bitmap_is_set(&unique_map, field->field_index)) + field->copy_from_tmp(table->s->rec_buff_length); + + DBUG_VOID_RETURN; +} + + +static +int cut_fields_for_portion_of_time(THD *thd, TABLE *table, + const vers_select_conds_t &period_conds) +{ + bool lcond= period_conds.field_start->val_datetime_packed(thd) + < period_conds.start.item->val_datetime_packed(thd); + bool rcond= period_conds.field_end->val_datetime_packed(thd) + > period_conds.end.item->val_datetime_packed(thd); + + Field *start_field= table->field[table->s->period.start_fieldno]; + Field *end_field= table->field[table->s->period.end_fieldno]; + + int res= 0; + if (lcond) + { + res= period_conds.start.item->save_in_field(start_field, true); + start_field->set_has_explicit_value(); + } + + if (likely(!res) && rcond) + { + res= period_conds.end.item->save_in_field(end_field, true); + end_field->set_has_explicit_value(); + } + + return res; +} + +/* + Process usual UPDATE + + SYNOPSIS + mysql_update() + thd thread handler + fields fields for update + values values of fields for update + conds WHERE clause expression + order_num number of elemen in ORDER BY clause + order ORDER BY clause list + limit limit clause + + RETURN + 0 - OK + 2 - privilege check and openning table passed, but we need to convert to + multi-update because of view substitution + 1 - error +*/ + +int mysql_update(THD *thd, + TABLE_LIST *table_list, + List<Item> &fields, + List<Item> &values, + COND *conds, + uint order_num, ORDER *order, + ha_rows limit, + bool ignore, + ha_rows *found_return, ha_rows *updated_return) +{ + bool using_limit= limit != HA_POS_ERROR; + bool safe_update= thd->variables.option_bits & OPTION_SAFE_UPDATES; + bool used_key_is_modified= FALSE, transactional_table; + bool will_batch= FALSE; + bool can_compare_record; + int res; + int error, loc_error; + ha_rows dup_key_found; + bool need_sort= TRUE; + bool reverse= FALSE; +#ifndef NO_EMBEDDED_ACCESS_CHECKS + privilege_t want_privilege(NO_ACL); +#endif + uint table_count= 0; + ha_rows updated, found; + key_map old_covering_keys; + TABLE *table; + SQL_SELECT *select= NULL; + SORT_INFO *file_sort= 0; + READ_RECORD info; + SELECT_LEX *select_lex= thd->lex->first_select_lex(); + ulonglong id; + List<Item> all_fields; + killed_state killed_status= NOT_KILLED; + bool has_triggers, binlog_is_row, do_direct_update= FALSE; + Update_plan query_plan(thd->mem_root); + Explain_update *explain; + TABLE_LIST *update_source_table; + query_plan.index= MAX_KEY; + query_plan.using_filesort= FALSE; + + // For System Versioning (may need to insert new fields to a table). + ha_rows rows_inserted= 0; + + DBUG_ENTER("mysql_update"); + + create_explain_query(thd->lex, thd->mem_root); + if (open_tables(thd, &table_list, &table_count, 0)) + DBUG_RETURN(1); + + /* Prepare views so they are handled correctly */ + if (mysql_handle_derived(thd->lex, DT_INIT)) + DBUG_RETURN(1); + + if (table_list->has_period() && table_list->is_view_or_derived()) + { + my_error(ER_IT_IS_A_VIEW, MYF(0), table_list->table_name.str); + DBUG_RETURN(TRUE); + } + + if (((update_source_table=unique_table(thd, table_list, + table_list->next_global, 0)) || + table_list->is_multitable())) + { + DBUG_ASSERT(update_source_table || table_list->view != 0); + DBUG_PRINT("info", ("Switch to multi-update")); + /* pass counter value */ + thd->lex->table_count= table_count; + if (thd->lex->period_conditions.is_set()) + { + my_error(ER_NOT_SUPPORTED_YET, MYF(0), + "updating and querying the same temporal periods table"); + + DBUG_RETURN(1); + } + + /* convert to multiupdate */ + DBUG_RETURN(2); + } + if (lock_tables(thd, table_list, table_count, 0)) + DBUG_RETURN(1); + + (void) read_statistics_for_tables_if_needed(thd, table_list); + + THD_STAGE_INFO(thd, stage_init_update); + if (table_list->handle_derived(thd->lex, DT_MERGE_FOR_INSERT)) + DBUG_RETURN(1); + if (table_list->handle_derived(thd->lex, DT_PREPARE)) + DBUG_RETURN(1); + + table= table_list->table; + + if (!table_list->single_table_updatable()) + { + my_error(ER_NON_UPDATABLE_TABLE, MYF(0), table_list->alias.str, "UPDATE"); + DBUG_RETURN(1); + } + + /* Calculate "table->covering_keys" based on the WHERE */ + table->covering_keys= table->s->keys_in_use; + table->opt_range_keys.clear_all(); + + query_plan.select_lex= thd->lex->first_select_lex(); + query_plan.table= table; +#ifndef NO_EMBEDDED_ACCESS_CHECKS + /* Force privilege re-checking for views after they have been opened. */ + want_privilege= (table_list->view ? UPDATE_ACL : + table_list->grant.want_privilege); +#endif + promote_select_describe_flag_if_needed(thd->lex); + + if (mysql_prepare_update(thd, table_list, &conds, order_num, order)) + DBUG_RETURN(1); + + if (table_list->has_period()) + { + if (!table_list->period_conditions.start.item->const_item() + || !table_list->period_conditions.end.item->const_item()) + { + my_error(ER_NOT_CONSTANT_EXPRESSION, MYF(0), "FOR PORTION OF"); + DBUG_RETURN(true); + } + table->no_cache= true; + } + + old_covering_keys= table->covering_keys; // Keys used in WHERE + /* Check the fields we are going to modify */ +#ifndef NO_EMBEDDED_ACCESS_CHECKS + table_list->grant.want_privilege= table->grant.want_privilege= want_privilege; + table_list->register_want_access(want_privilege); +#endif + /* 'Unfix' fields to allow correct marking by the setup_fields function. */ + if (table_list->is_view()) + unfix_fields(fields); + + if (setup_fields_with_no_wrap(thd, Ref_ptr_array(), + fields, MARK_COLUMNS_WRITE, 0, 0)) + DBUG_RETURN(1); /* purecov: inspected */ + if (check_fields(thd, table_list, fields, table_list->view)) + { + DBUG_RETURN(1); + } + bool has_vers_fields= table->vers_check_update(fields); + if (check_key_in_view(thd, table_list)) + { + my_error(ER_NON_UPDATABLE_TABLE, MYF(0), table_list->alias.str, "UPDATE"); + DBUG_RETURN(1); + } + + if (table->default_field) + table->mark_default_fields_for_write(false); + +#ifndef NO_EMBEDDED_ACCESS_CHECKS + /* Check values */ + table_list->grant.want_privilege= table->grant.want_privilege= + (SELECT_ACL & ~table->grant.privilege); +#endif + if (setup_fields(thd, Ref_ptr_array(), values, MARK_COLUMNS_READ, 0, NULL, 0)) + { + free_underlaid_joins(thd, select_lex); + DBUG_RETURN(1); /* purecov: inspected */ + } + + if (check_unique_table(thd, table_list)) + DBUG_RETURN(TRUE); + + switch_to_nullable_trigger_fields(fields, table); + switch_to_nullable_trigger_fields(values, table); + + /* Apply the IN=>EXISTS transformation to all subqueries and optimize them */ + if (select_lex->optimize_unflattened_subqueries(false)) + DBUG_RETURN(TRUE); + + if (select_lex->inner_refs_list.elements && + fix_inner_refs(thd, all_fields, select_lex, select_lex->ref_pointer_array)) + DBUG_RETURN(1); + + if (conds) + { + Item::cond_result cond_value; + conds= conds->remove_eq_conds(thd, &cond_value, true); + if (cond_value == Item::COND_FALSE) + { + limit= 0; // Impossible WHERE + query_plan.set_impossible_where(); + if (thd->lex->describe || thd->lex->analyze_stmt) + goto produce_explain_and_leave; + } + } + + // Don't count on usage of 'only index' when calculating which key to use + table->covering_keys.clear_all(); + +#ifdef WITH_PARTITION_STORAGE_ENGINE + if (prune_partitions(thd, table, conds)) + { + free_underlaid_joins(thd, select_lex); + + query_plan.set_no_partitions(); + if (thd->lex->describe || thd->lex->analyze_stmt) + goto produce_explain_and_leave; + if (thd->is_error()) + DBUG_RETURN(1); + + my_ok(thd); // No matching records + DBUG_RETURN(0); + } +#endif + /* Update the table->file->stats.records number */ + table->file->info(HA_STATUS_VARIABLE | HA_STATUS_NO_LOCK); + set_statistics_for_table(thd, table); + + select= make_select(table, 0, 0, conds, (SORT_INFO*) 0, 0, &error); + if (unlikely(error || !limit || thd->is_error() || + (select && select->check_quick(thd, safe_update, limit)))) + { + query_plan.set_impossible_where(); + if (thd->lex->describe || thd->lex->analyze_stmt) + goto produce_explain_and_leave; + + delete select; + free_underlaid_joins(thd, select_lex); + /* + There was an error or the error was already sent by + the quick select evaluation. + TODO: Add error code output parameter to Item::val_xxx() methods. + Currently they rely on the user checking DA for + errors when unwinding the stack after calling Item::val_xxx(). + */ + if (error || thd->is_error()) + { + DBUG_RETURN(1); // Error in where + } + my_ok(thd); // No matching records + DBUG_RETURN(0); + } + + /* If running in safe sql mode, don't allow updates without keys */ + if (table->opt_range_keys.is_clear_all()) + { + thd->set_status_no_index_used(); + if (safe_update && !using_limit) + { + my_message(ER_UPDATE_WITHOUT_KEY_IN_SAFE_MODE, + ER_THD(thd, ER_UPDATE_WITHOUT_KEY_IN_SAFE_MODE), MYF(0)); + goto err; + } + } + if (unlikely(init_ftfuncs(thd, select_lex, 1))) + goto err; + + if (table_list->has_period()) + { + table->use_all_columns(); + table->rpl_write_set= table->write_set; + } + else + { + table->mark_columns_needed_for_update(); + } + + table->update_const_key_parts(conds); + order= simple_remove_const(order, conds); + query_plan.scanned_rows= select? select->records: table->file->stats.records; + + if (select && select->quick && select->quick->unique_key_range()) + { + /* Single row select (always "ordered"): Ok to use with key field UPDATE */ + need_sort= FALSE; + query_plan.index= MAX_KEY; + used_key_is_modified= FALSE; + } + else + { + ha_rows scanned_limit= query_plan.scanned_rows; + table->no_keyread= 1; + query_plan.index= get_index_for_order(order, table, select, limit, + &scanned_limit, &need_sort, + &reverse); + table->no_keyread= 0; + if (!need_sort) + query_plan.scanned_rows= scanned_limit; + + if (select && select->quick) + { + DBUG_ASSERT(need_sort || query_plan.index == select->quick->index); + used_key_is_modified= (!select->quick->unique_key_range() && + select->quick->is_keys_used(table->write_set)); + } + else + { + if (need_sort) + { + /* Assign table scan index to check below for modified key fields: */ + query_plan.index= table->file->key_used_on_scan; + } + if (query_plan.index != MAX_KEY) + { + /* Check if we are modifying a key that we are used to search with: */ + used_key_is_modified= is_key_used(table, query_plan.index, + table->write_set); + } + } + } + + /* + Query optimization is finished at this point. + - Save the decisions in the query plan + - if we're running EXPLAIN UPDATE, get out + */ + query_plan.select= select; + query_plan.possible_keys= select? select->possible_keys: key_map(0); + + if (used_key_is_modified || order || + partition_key_modified(table, table->write_set)) + { + if (order && need_sort) + query_plan.using_filesort= true; + else + query_plan.using_io_buffer= true; + } + + /* + Ok, we have generated a query plan for the UPDATE. + - if we're running EXPLAIN UPDATE, goto produce explain output + - otherwise, execute the query plan + */ + if (thd->lex->describe) + goto produce_explain_and_leave; + if (!(explain= query_plan.save_explain_update_data(query_plan.mem_root, thd))) + goto err; + + ANALYZE_START_TRACKING(thd, &explain->command_tracker); + + DBUG_EXECUTE_IF("show_explain_probe_update_exec_start", + dbug_serve_apcs(thd, 1);); + + has_triggers= (table->triggers && + (table->triggers->has_triggers(TRG_EVENT_UPDATE, + TRG_ACTION_BEFORE) || + table->triggers->has_triggers(TRG_EVENT_UPDATE, + TRG_ACTION_AFTER))); + + if (table_list->has_period()) + has_triggers= table->triggers && + (table->triggers->has_triggers(TRG_EVENT_INSERT, + TRG_ACTION_BEFORE) + || table->triggers->has_triggers(TRG_EVENT_INSERT, + TRG_ACTION_AFTER) + || has_triggers); + DBUG_PRINT("info", ("has_triggers: %s", has_triggers ? "TRUE" : "FALSE")); + binlog_is_row= thd->is_current_stmt_binlog_format_row(); + DBUG_PRINT("info", ("binlog_is_row: %s", binlog_is_row ? "TRUE" : "FALSE")); + + if (!(select && select->quick)) + status_var_increment(thd->status_var.update_scan_count); + + /* + We can use direct update (update that is done silently in the handler) + if none of the following conditions are true: + - There are triggers + - There is binary logging + - using_io_buffer + - This means that the partition changed or the key we want + to use for scanning the table is changed + - ignore is set + - Direct updates don't return the number of ignored rows + - There is a virtual not stored column in the WHERE clause + - Changing a field used by a stored virtual column, which + would require the column to be recalculated. + - ORDER BY or LIMIT + - As this requires the rows to be updated in a specific order + - Note that Spider can handle ORDER BY and LIMIT in a cluster with + one data node. These conditions are therefore checked in + direct_update_rows_init(). + - Update fields include a unique timestamp field + - The storage engine may not be able to avoid false duplicate key + errors. This condition is checked in direct_update_rows_init(). + + Direct update does not require a WHERE clause + + Later we also ensure that we are only using one table (no sub queries) + */ + DBUG_PRINT("info", ("HA_CAN_DIRECT_UPDATE_AND_DELETE: %s", (table->file->ha_table_flags() & HA_CAN_DIRECT_UPDATE_AND_DELETE) ? "TRUE" : "FALSE")); + DBUG_PRINT("info", ("using_io_buffer: %s", query_plan.using_io_buffer ? "TRUE" : "FALSE")); + DBUG_PRINT("info", ("ignore: %s", ignore ? "TRUE" : "FALSE")); + DBUG_PRINT("info", ("virtual_columns_marked_for_read: %s", table->check_virtual_columns_marked_for_read() ? "TRUE" : "FALSE")); + DBUG_PRINT("info", ("virtual_columns_marked_for_write: %s", table->check_virtual_columns_marked_for_write() ? "TRUE" : "FALSE")); + if ((table->file->ha_table_flags() & HA_CAN_DIRECT_UPDATE_AND_DELETE) && + !has_triggers && !binlog_is_row && + !query_plan.using_io_buffer && !ignore && + !table->check_virtual_columns_marked_for_read() && + !table->check_virtual_columns_marked_for_write()) + { + DBUG_PRINT("info", ("Trying direct update")); + if (select && select->cond && + (select->cond->used_tables() == table->map)) + { + DBUG_ASSERT(!table->file->pushed_cond); + if (!table->file->cond_push(select->cond)) + table->file->pushed_cond= select->cond; + } + + if (!table->file->info_push(INFO_KIND_UPDATE_FIELDS, &fields) && + !table->file->info_push(INFO_KIND_UPDATE_VALUES, &values) && + !table->file->direct_update_rows_init(&fields)) + { + do_direct_update= TRUE; + + /* Direct update is not using_filesort and is not using_io_buffer */ + goto update_begin; + } + } + + if (query_plan.using_filesort || query_plan.using_io_buffer) + { + /* + We can't update table directly; We must first search after all + matching rows before updating the table! + + note: We avoid sorting if we sort on the used index + */ + if (query_plan.using_filesort) + { + /* + Doing an ORDER BY; Let filesort find and sort the rows we are going + to update + NOTE: filesort will call table->prepare_for_position() + */ + Filesort fsort(order, limit, true, select); + + Filesort_tracker *fs_tracker= + thd->lex->explain->get_upd_del_plan()->filesort_tracker; + + if (!(file_sort= filesort(thd, table, &fsort, fs_tracker))) + goto err; + thd->inc_examined_row_count(file_sort->examined_rows); + + /* + Filesort has already found and selected the rows we want to update, + so we don't need the where clause + */ + delete select; + select= 0; + } + else + { + MY_BITMAP *save_read_set= table->read_set; + MY_BITMAP *save_write_set= table->write_set; + + if (query_plan.index < MAX_KEY && old_covering_keys.is_set(query_plan.index)) + table->prepare_for_keyread(query_plan.index); + else + table->use_all_columns(); + + /* + We are doing a search on a key that is updated. In this case + we go trough the matching rows, save a pointer to them and + update these in a separate loop based on the pointer. + */ + explain->buf_tracker.on_scan_init(); + IO_CACHE tempfile; + if (open_cached_file(&tempfile, mysql_tmpdir,TEMP_PREFIX, + DISK_BUFFER_SIZE, MYF(MY_WME))) + goto err; + + /* If quick select is used, initialize it before retrieving rows. */ + if (select && select->quick && select->quick->reset()) + { + close_cached_file(&tempfile); + goto err; + } + + table->file->try_semi_consistent_read(1); + + /* + When we get here, we have one of the following options: + A. query_plan.index == MAX_KEY + This means we should use full table scan, and start it with + init_read_record call + B. query_plan.index != MAX_KEY + B.1 quick select is used, start the scan with init_read_record + B.2 quick select is not used, this is full index scan (with LIMIT) + Full index scan must be started with init_read_record_idx + */ + + if (query_plan.index == MAX_KEY || (select && select->quick)) + error= init_read_record(&info, thd, table, select, NULL, 0, 1, FALSE); + else + error= init_read_record_idx(&info, thd, table, 1, query_plan.index, + reverse); + + if (unlikely(error)) + { + close_cached_file(&tempfile); + goto err; + } + + THD_STAGE_INFO(thd, stage_searching_rows_for_update); + ha_rows tmp_limit= limit; + + while (likely(!(error=info.read_record())) && likely(!thd->killed)) + { + explain->buf_tracker.on_record_read(); + thd->inc_examined_row_count(1); + if (!select || (error= select->skip_record(thd)) > 0) + { + if (table->file->ha_was_semi_consistent_read()) + continue; /* repeat the read of the same row if it still exists */ + + explain->buf_tracker.on_record_after_where(); + table->file->position(table->record[0]); + if (unlikely(my_b_write(&tempfile,table->file->ref, + table->file->ref_length))) + { + error=1; /* purecov: inspected */ + break; /* purecov: inspected */ + } + if (!--limit && using_limit) + { + error= -1; + break; + } + } + else + { + /* + Don't try unlocking the row if skip_record reported an + error since in this case the transaction might have been + rolled back already. + */ + if (unlikely(error < 0)) + { + /* Fatal error from select->skip_record() */ + error= 1; + break; + } + else + table->file->unlock_row(); + } + } + if (unlikely(thd->killed) && !error) + error= 1; // Aborted + limit= tmp_limit; + table->file->try_semi_consistent_read(0); + end_read_record(&info); + + /* Change select to use tempfile */ + if (select) + { + delete select->quick; + if (select->free_cond) + delete select->cond; + select->quick=0; + select->cond=0; + } + else + { + if (!(select= new SQL_SELECT)) + goto err; + select->head=table; + } + + if (unlikely(reinit_io_cache(&tempfile,READ_CACHE,0L,0,0))) + error= 1; /* purecov: inspected */ + select->file= tempfile; // Read row ptrs from this file + if (unlikely(error >= 0)) + goto err; + + table->file->ha_end_keyread(); + table->column_bitmaps_set(save_read_set, save_write_set); + } + } + +update_begin: + if (ignore) + table->file->extra(HA_EXTRA_IGNORE_DUP_KEY); + + if (select && select->quick && select->quick->reset()) + goto err; + table->file->try_semi_consistent_read(1); + if (init_read_record(&info, thd, table, select, file_sort, 0, 1, FALSE)) + goto err; + + updated= found= 0; + /* + Generate an error (in TRADITIONAL mode) or warning + when trying to set a NOT NULL field to NULL. + */ + thd->count_cuted_fields= CHECK_FIELD_WARN; + thd->cuted_fields=0L; + + transactional_table= table->file->has_transactions_and_rollback(); + thd->abort_on_warning= !ignore && thd->is_strict_mode(); + + if (do_direct_update) + { + /* Direct updating is supported */ + ha_rows update_rows= 0, found_rows= 0; + DBUG_PRINT("info", ("Using direct update")); + table->reset_default_fields(); + if (unlikely(!(error= table->file->ha_direct_update_rows(&update_rows, + &found_rows)))) + error= -1; + updated= update_rows; + found= found_rows; + if (found < updated) + found= updated; + goto update_end; + } + + if ((table->file->ha_table_flags() & HA_CAN_FORCE_BULK_UPDATE) && + !table->prepare_triggers_for_update_stmt_or_event()) + will_batch= !table->file->start_bulk_update(); + + /* + Assure that we can use position() + if we need to create an error message. + */ + if (table->file->ha_table_flags() & HA_PARTIAL_COLUMN_READ) + table->prepare_for_position(); + + table->reset_default_fields(); + + /* + We can use compare_record() to optimize away updates if + the table handler is returning all columns OR if + if all updated columns are read + */ + can_compare_record= records_are_comparable(table); + explain->tracker.on_scan_init(); + + table->file->prepare_for_insert(1); + DBUG_ASSERT(table->file->inited != handler::NONE); + + THD_STAGE_INFO(thd, stage_updating); + while (!(error=info.read_record()) && !thd->killed) + { + explain->tracker.on_record_read(); + thd->inc_examined_row_count(1); + if (!select || select->skip_record(thd) > 0) + { + if (table->file->ha_was_semi_consistent_read()) + continue; /* repeat the read of the same row if it still exists */ + + explain->tracker.on_record_after_where(); + store_record(table,record[1]); + + if (table_list->has_period()) + cut_fields_for_portion_of_time(thd, table, + table_list->period_conditions); + + if (fill_record_n_invoke_before_triggers(thd, table, fields, values, 0, + TRG_EVENT_UPDATE)) + break; /* purecov: inspected */ + + found++; + + bool record_was_same= false; + bool need_update= !can_compare_record || compare_record(table); + + if (need_update) + { + if (table->versioned(VERS_TIMESTAMP) && + thd->lex->sql_command == SQLCOM_DELETE) + table->vers_update_end(); + + if ((res= table_list->view_check_option(thd, ignore)) != + VIEW_CHECK_OK) + { + found--; + if (res == VIEW_CHECK_SKIP) + continue; + else if (res == VIEW_CHECK_ERROR) + { + error= 1; + break; + } + } + if (will_batch) + { + /* + Typically a batched handler can execute the batched jobs when: + 1) When specifically told to do so + 2) When it is not a good idea to batch anymore + 3) When it is necessary to send batch for other reasons + (One such reason is when READ's must be performed) + + 1) is covered by exec_bulk_update calls. + 2) and 3) is handled by the bulk_update_row method. + + bulk_update_row can execute the updates including the one + defined in the bulk_update_row or not including the row + in the call. This is up to the handler implementation and can + vary from call to call. + + The dup_key_found reports the number of duplicate keys found + in those updates actually executed. It only reports those if + the extra call with HA_EXTRA_IGNORE_DUP_KEY have been issued. + If this hasn't been issued it returns an error code and can + ignore this number. Thus any handler that implements batching + for UPDATE IGNORE must also handle this extra call properly. + + If a duplicate key is found on the record included in this + call then it should be included in the count of dup_key_found + and error should be set to 0 (only if these errors are ignored). + */ + DBUG_PRINT("info", ("Batched update")); + error= table->file->ha_bulk_update_row(table->record[1], + table->record[0], + &dup_key_found); + limit+= dup_key_found; + updated-= dup_key_found; + } + else + { + /* Non-batched update */ + error= table->file->ha_update_row(table->record[1], + table->record[0]); + } + + record_was_same= error == HA_ERR_RECORD_IS_THE_SAME; + if (unlikely(record_was_same)) + { + error= 0; + } + else if (likely(!error)) + { + if (has_vers_fields && table->versioned(VERS_TRX_ID)) + rows_inserted++; + updated++; + } + + if (likely(!error) && !record_was_same && table_list->has_period()) + { + store_record(table, record[2]); + restore_record(table, record[1]); + error= table->insert_portion_of_time(thd, + table_list->period_conditions, + &rows_inserted); + restore_record(table, record[2]); + } + + if (unlikely(error) && + (!ignore || table->file->is_fatal_error(error, HA_CHECK_ALL))) + { + goto error; + } + } + + if (likely(!error) && has_vers_fields && table->versioned(VERS_TIMESTAMP)) + { + store_record(table, record[2]); + table->mark_columns_per_binlog_row_image(); + error= vers_insert_history_row(table); + restore_record(table, record[2]); + if (unlikely(error)) + { +error: + /* + If (ignore && error is ignorable) we don't have to + do anything; otherwise... + */ + myf flags= 0; + + if (table->file->is_fatal_error(error, HA_CHECK_ALL)) + flags|= ME_FATAL; /* Other handler errors are fatal */ + + prepare_record_for_error_message(error, table); + table->file->print_error(error,MYF(flags)); + error= 1; + break; + } + rows_inserted++; + } + + if (table->triggers && + unlikely(table->triggers->process_triggers(thd, TRG_EVENT_UPDATE, + TRG_ACTION_AFTER, TRUE))) + { + error= 1; + break; + } + + if (!--limit && using_limit) + { + /* + We have reached end-of-file in most common situations where no + batching has occurred and if batching was supposed to occur but + no updates were made and finally when the batch execution was + performed without error and without finding any duplicate keys. + If the batched updates were performed with errors we need to + check and if no error but duplicate key's found we need to + continue since those are not counted for in limit. + */ + if (will_batch && + ((error= table->file->exec_bulk_update(&dup_key_found)) || + dup_key_found)) + { + if (error) + { + /* purecov: begin inspected */ + /* + The handler should not report error of duplicate keys if they + are ignored. This is a requirement on batching handlers. + */ + prepare_record_for_error_message(error, table); + table->file->print_error(error,MYF(0)); + error= 1; + break; + /* purecov: end */ + } + /* + Either an error was found and we are ignoring errors or there + were duplicate keys found. In both cases we need to correct + the counters and continue the loop. + */ + limit= dup_key_found; //limit is 0 when we get here so need to + + updated-= dup_key_found; + } + else + { + error= -1; // Simulate end of file + break; + } + } + } + /* + Don't try unlocking the row if skip_record reported an error since in + this case the transaction might have been rolled back already. + */ + else if (likely(!thd->is_error())) + table->file->unlock_row(); + else + { + error= 1; + break; + } + thd->get_stmt_da()->inc_current_row_for_warning(); + if (unlikely(thd->is_error())) + { + error= 1; + break; + } + } + ANALYZE_STOP_TRACKING(thd, &explain->command_tracker); + table->auto_increment_field_not_null= FALSE; + dup_key_found= 0; + /* + Caching the killed status to pass as the arg to query event constuctor; + The cached value can not change whereas the killed status can + (externally) since this point and change of the latter won't affect + binlogging. + It's assumed that if an error was set in combination with an effective + killed status then the error is due to killing. + */ + killed_status= thd->killed; // get the status of the volatile + // simulated killing after the loop must be ineffective for binlogging + DBUG_EXECUTE_IF("simulate_kill_bug27571", + { + thd->set_killed(KILL_QUERY); + };); + error= (killed_status == NOT_KILLED)? error : 1; + + if (likely(error) && + will_batch && + (loc_error= table->file->exec_bulk_update(&dup_key_found))) + /* + An error has occurred when a batched update was performed and returned + an error indication. It cannot be an allowed duplicate key error since + we require the batching handler to treat this as a normal behavior. + + Otherwise we simply remove the number of duplicate keys records found + in the batched update. + */ + { + /* purecov: begin inspected */ + prepare_record_for_error_message(loc_error, table); + table->file->print_error(loc_error,MYF(ME_FATAL)); + error= 1; + /* purecov: end */ + } + else + updated-= dup_key_found; + if (will_batch) + table->file->end_bulk_update(); + +update_end: + table->file->try_semi_consistent_read(0); + + if (!transactional_table && updated > 0) + thd->transaction->stmt.modified_non_trans_table= TRUE; + + end_read_record(&info); + delete select; + select= NULL; + THD_STAGE_INFO(thd, stage_end); + if (table_list->has_period()) + table->file->ha_release_auto_increment(); + (void) table->file->extra(HA_EXTRA_NO_IGNORE_DUP_KEY); + + /* + Invalidate the table in the query cache if something changed. + This must be before binlog writing and ha_autocommit_... + */ + if (updated) + { + query_cache_invalidate3(thd, table_list, 1); + } + + if (thd->transaction->stmt.modified_non_trans_table) + thd->transaction->all.modified_non_trans_table= TRUE; + thd->transaction->all.m_unsafe_rollback_flags|= + (thd->transaction->stmt.m_unsafe_rollback_flags & THD_TRANS::DID_WAIT); + + /* + error < 0 means really no error at all: we processed all rows until the + last one without error. error > 0 means an error (e.g. unique key + violation and no IGNORE or REPLACE). error == 0 is also an error (if + preparing the record or invoking before triggers fails). See + ha_autocommit_or_rollback(error>=0) and DBUG_RETURN(error>=0) below. + Sometimes we want to binlog even if we updated no rows, in case user used + it to be sure master and slave are in same state. + */ + if (likely(error < 0) || thd->transaction->stmt.modified_non_trans_table) + { + if (WSREP_EMULATE_BINLOG(thd) || mysql_bin_log.is_open()) + { + int errcode= 0; + if (likely(error < 0)) + thd->clear_error(); + else + errcode= query_error_code(thd, killed_status == NOT_KILLED); + + ScopedStatementReplication scoped_stmt_rpl( + table->versioned(VERS_TRX_ID) ? thd : NULL); + + if (thd->binlog_query(THD::ROW_QUERY_TYPE, + thd->query(), thd->query_length(), + transactional_table, FALSE, FALSE, errcode) > 0) + { + error=1; // Rollback update + } + } + } + DBUG_ASSERT(transactional_table || !updated || thd->transaction->stmt.modified_non_trans_table); + free_underlaid_joins(thd, select_lex); + delete file_sort; + if (table->file->pushed_cond) + { + table->file->pushed_cond= 0; + table->file->cond_pop(); + } + + /* If LAST_INSERT_ID(X) was used, report X */ + id= thd->arg_of_last_insert_id_function ? + thd->first_successful_insert_id_in_prev_stmt : 0; + + if (likely(error < 0) && likely(!thd->lex->analyze_stmt)) + { + char buff[MYSQL_ERRMSG_SIZE]; + if (!table->versioned(VERS_TIMESTAMP) && !table_list->has_period()) + my_snprintf(buff, sizeof(buff), ER_THD(thd, ER_UPDATE_INFO), (ulong) found, + (ulong) updated, + (ulong) thd->get_stmt_da()->current_statement_warn_count()); + else + my_snprintf(buff, sizeof(buff), + ER_THD(thd, ER_UPDATE_INFO_WITH_SYSTEM_VERSIONING), + (ulong) found, (ulong) updated, (ulong) rows_inserted, + (ulong) thd->get_stmt_da()->current_statement_warn_count()); + my_ok(thd, (thd->client_capabilities & CLIENT_FOUND_ROWS) ? found : updated, + id, buff); + DBUG_PRINT("info",("%ld records updated", (long) updated)); + } + thd->count_cuted_fields= CHECK_FIELD_IGNORE; /* calc cuted fields */ + thd->abort_on_warning= 0; + if (thd->lex->current_select->first_cond_optimization) + { + thd->lex->current_select->save_leaf_tables(thd); + thd->lex->current_select->first_cond_optimization= 0; + } + *found_return= found; + *updated_return= updated; + + if (unlikely(thd->lex->analyze_stmt)) + goto emit_explain_and_leave; + + DBUG_RETURN((error >= 0 || thd->is_error()) ? 1 : 0); + +err: + delete select; + delete file_sort; + free_underlaid_joins(thd, select_lex); + table->file->ha_end_keyread(); + if (table->file->pushed_cond) + table->file->cond_pop(); + thd->abort_on_warning= 0; + DBUG_RETURN(1); + +produce_explain_and_leave: + /* + We come here for various "degenerate" query plans: impossible WHERE, + no-partitions-used, impossible-range, etc. + */ + if (unlikely(!query_plan.save_explain_update_data(query_plan.mem_root, thd))) + goto err; + +emit_explain_and_leave: + int err2= thd->lex->explain->send_explain(thd); + + delete select; + free_underlaid_joins(thd, select_lex); + DBUG_RETURN((err2 || thd->is_error()) ? 1 : 0); +} + +/* + Prepare items in UPDATE statement + + SYNOPSIS + mysql_prepare_update() + thd - thread handler + table_list - global/local table list + conds - conditions + order_num - number of ORDER BY list entries + order - ORDER BY clause list + + RETURN VALUE + FALSE OK + TRUE error +*/ +bool mysql_prepare_update(THD *thd, TABLE_LIST *table_list, + Item **conds, uint order_num, ORDER *order) +{ + Item *fake_conds= 0; +#ifndef NO_EMBEDDED_ACCESS_CHECKS + TABLE *table= table_list->table; +#endif + List<Item> all_fields; + SELECT_LEX *select_lex= thd->lex->first_select_lex(); + DBUG_ENTER("mysql_prepare_update"); + +#ifndef NO_EMBEDDED_ACCESS_CHECKS + table_list->grant.want_privilege= table->grant.want_privilege= + (SELECT_ACL & ~table->grant.privilege); + table_list->register_want_access(SELECT_ACL); +#endif + + thd->lex->allow_sum_func.clear_all(); + + if (table_list->has_period() && + select_lex->period_setup_conds(thd, table_list)) + DBUG_RETURN(true); + + DBUG_ASSERT(table_list->table); + // conds could be cached from previous SP call + DBUG_ASSERT(!table_list->vers_conditions.need_setup() || + !*conds || thd->stmt_arena->is_stmt_execute()); + if (select_lex->vers_setup_conds(thd, table_list)) + DBUG_RETURN(TRUE); + + *conds= select_lex->where; + + /* + We do not call DT_MERGE_FOR_INSERT because it has no sense for simple + (not multi-) update + */ + if (mysql_handle_derived(thd->lex, DT_PREPARE)) + DBUG_RETURN(TRUE); + + if (setup_tables_and_check_access(thd, &select_lex->context, + &select_lex->top_join_list, table_list, + select_lex->leaf_tables, + FALSE, UPDATE_ACL, SELECT_ACL, TRUE) || + setup_conds(thd, table_list, select_lex->leaf_tables, conds) || + select_lex->setup_ref_array(thd, order_num) || + setup_order(thd, select_lex->ref_pointer_array, + table_list, all_fields, all_fields, order) || + setup_ftfuncs(select_lex)) + DBUG_RETURN(TRUE); + + + select_lex->fix_prepare_information(thd, conds, &fake_conds); + DBUG_RETURN(FALSE); +} + +/** + Check that we are not using table that we are updating in a sub select + + @param thd Thread handle + @param table_list List of table with first to check + + @retval TRUE Error + @retval FALSE OK +*/ +bool check_unique_table(THD *thd, TABLE_LIST *table_list) +{ + TABLE_LIST *duplicate; + DBUG_ENTER("check_unique_table"); + if ((duplicate= unique_table(thd, table_list, table_list->next_global, 0))) + { + update_non_unique_table_error(table_list, "UPDATE", duplicate); + DBUG_RETURN(TRUE); + } + DBUG_RETURN(FALSE); +} + +/*************************************************************************** + Update multiple tables from join +***************************************************************************/ + +/* + Get table map for list of Item_field +*/ + +static table_map get_table_map(List<Item> *items) +{ + List_iterator_fast<Item> item_it(*items); + Item_field *item; + table_map map= 0; + + while ((item= (Item_field *) item_it++)) + map|= item->all_used_tables(); + DBUG_PRINT("info", ("table_map: 0x%08lx", (long) map)); + return map; +} + +/** + If one row is updated through two different aliases and the first + update physically moves the row, the second update will error + because the row is no longer located where expected. This function + checks if the multiple-table update is about to do that and if so + returns with an error. + + The following update operations physically moves rows: + 1) Update of a column in a clustered primary key + 2) Update of a column used to calculate which partition the row belongs to + + This function returns with an error if both of the following are + true: + + a) A table in the multiple-table update statement is updated + through multiple aliases (including views) + b) At least one of the updates on the table from a) may physically + moves the row. Note: Updating a column used to calculate which + partition a row belongs to does not necessarily mean that the + row is moved. The new value may or may not belong to the same + partition. + + @param leaves First leaf table + @param tables_for_update Map of tables that are updated + + @return + true if the update is unsafe, in which case an error message is also set, + false otherwise. +*/ +static +bool unsafe_key_update(List<TABLE_LIST> leaves, table_map tables_for_update) +{ + List_iterator_fast<TABLE_LIST> it(leaves), it2(leaves); + TABLE_LIST *tl, *tl2; + + while ((tl= it++)) + { + if (!tl->is_jtbm() && (tl->table->map & tables_for_update)) + { + TABLE *table1= tl->table; + bool primkey_clustered= (table1->file-> + pk_is_clustering_key(table1->s->primary_key)); + + bool table_partitioned= false; +#ifdef WITH_PARTITION_STORAGE_ENGINE + table_partitioned= (table1->part_info != NULL); +#endif + + if (!table_partitioned && !primkey_clustered) + continue; + + it2.rewind(); + while ((tl2= it2++)) + { + if (tl2->is_jtbm()) + continue; + /* + Look at "next" tables only since all previous tables have + already been checked + */ + TABLE *table2= tl2->table; + if (tl2 != tl && + table2->map & tables_for_update && table1->s == table2->s) + { + // A table is updated through two aliases + if (table_partitioned && + (partition_key_modified(table1, table1->write_set) || + partition_key_modified(table2, table2->write_set))) + { + // Partitioned key is updated + my_error(ER_MULTI_UPDATE_KEY_CONFLICT, MYF(0), + tl->top_table()->alias.str, + tl2->top_table()->alias.str); + return true; + } + + if (primkey_clustered) + { + // The primary key can cover multiple columns + KEY key_info= table1->key_info[table1->s->primary_key]; + KEY_PART_INFO *key_part= key_info.key_part; + KEY_PART_INFO *key_part_end= key_part + key_info.user_defined_key_parts; + + for (;key_part != key_part_end; ++key_part) + { + if (bitmap_is_set(table1->write_set, key_part->fieldnr-1) || + bitmap_is_set(table2->write_set, key_part->fieldnr-1)) + { + // Clustered primary key is updated + my_error(ER_MULTI_UPDATE_KEY_CONFLICT, MYF(0), + tl->top_table()->alias.str, + tl2->top_table()->alias.str); + return true; + } + } + } + } + } + } + } + return false; +} + +/** + Check if there is enough privilege on specific table used by the + main select list of multi-update directly or indirectly (through + a view). + + @param[in] thd Thread context. + @param[in] table Table list element for the table. + @param[in] tables_for_update Bitmap with tables being updated. + @param[in/out] updated_arg Set to true if table in question is + updated, also set to true if it is + a view and one of its underlying + tables is updated. Should be + initialized to false by the caller + before a sequence of calls to this + function. + + @note To determine which tables/views are updated we have to go from + leaves to root since tables_for_update contains map of leaf + tables being updated and doesn't include non-leaf tables + (fields are already resolved to leaf tables). + + @retval false - Success, all necessary privileges on all tables are + present or might be present on column-level. + @retval true - Failure, some necessary privilege on some table is + missing. +*/ + +static bool multi_update_check_table_access(THD *thd, TABLE_LIST *table, + table_map tables_for_update, + bool *updated_arg) +{ + if (table->view) + { + bool updated= false; + /* + If it is a mergeable view then we need to check privileges on its + underlying tables being merged (including views). We also need to + check if any of them is updated in order to find if this view is + updated. + If it is a non-mergeable view then it can't be updated. + */ + DBUG_ASSERT(table->merge_underlying_list || + (!table->updatable && + !(table->table->map & tables_for_update))); + + for (TABLE_LIST *tbl= table->merge_underlying_list; tbl; + tbl= tbl->next_local) + { + if (multi_update_check_table_access(thd, tbl, tables_for_update, + &updated)) + { + tbl->hide_view_error(thd); + return true; + } + } + if (check_table_access(thd, updated ? UPDATE_ACL: SELECT_ACL, table, + FALSE, 1, FALSE)) + return true; + *updated_arg|= updated; + /* We only need SELECT privilege for columns in the values list. */ + table->grant.want_privilege= SELECT_ACL & ~table->grant.privilege; + } + else + { + /* Must be a base or derived table. */ + const bool updated= table->table->map & tables_for_update; + if (check_table_access(thd, updated ? UPDATE_ACL : SELECT_ACL, table, + FALSE, 1, FALSE)) + return true; + *updated_arg|= updated; + /* We only need SELECT privilege for columns in the values list. */ + if (!table->derived) + { + table->grant.want_privilege= SELECT_ACL & ~table->grant.privilege; + table->table->grant.want_privilege= (SELECT_ACL & + ~table->table->grant.privilege); + } + } + return false; +} + + +class Multiupdate_prelocking_strategy : public DML_prelocking_strategy +{ + bool done; + bool has_prelocking_list; +public: + void reset(THD *thd); + bool handle_end(THD *thd); +}; + +void Multiupdate_prelocking_strategy::reset(THD *thd) +{ + done= false; + has_prelocking_list= thd->lex->requires_prelocking(); +} + +/** + Determine what tables could be updated in the multi-update + + For these tables we'll need to open triggers and continue prelocking + until all is open. +*/ +bool Multiupdate_prelocking_strategy::handle_end(THD *thd) +{ + DBUG_ENTER("Multiupdate_prelocking_strategy::handle_end"); + if (done) + DBUG_RETURN(0); + + LEX *lex= thd->lex; + SELECT_LEX *select_lex= lex->first_select_lex(); + TABLE_LIST *table_list= lex->query_tables, *tl; + + done= true; + + if (mysql_handle_derived(lex, DT_INIT) || + mysql_handle_derived(lex, DT_MERGE_FOR_INSERT) || + mysql_handle_derived(lex, DT_PREPARE)) + DBUG_RETURN(1); + + /* + setup_tables() need for VIEWs. JOIN::prepare() will call setup_tables() + second time, but this call will do nothing (there are check for second + call in setup_tables()). + */ + + if (setup_tables_and_check_access(thd, &select_lex->context, + &select_lex->top_join_list, table_list, select_lex->leaf_tables, + FALSE, UPDATE_ACL, SELECT_ACL, TRUE)) + DBUG_RETURN(1); + + List<Item> *fields= &lex->first_select_lex()->item_list; + if (setup_fields_with_no_wrap(thd, Ref_ptr_array(), + *fields, MARK_COLUMNS_WRITE, 0, 0)) + DBUG_RETURN(1); + + // Check if we have a view in the list ... + for (tl= table_list; tl ; tl= tl->next_local) + if (tl->view) + break; + // ... and pass this knowlage in check_fields call + if (check_fields(thd, table_list, *fields, tl != NULL )) + DBUG_RETURN(1); + + table_map tables_for_update= thd->table_map_for_update= get_table_map(fields); + + if (unsafe_key_update(select_lex->leaf_tables, tables_for_update)) + DBUG_RETURN(1); + + /* + Setup timestamp handling and locking mode + */ + List_iterator<TABLE_LIST> ti(lex->first_select_lex()->leaf_tables); + const bool using_lock_tables= thd->locked_tables_mode != LTM_NONE; + while ((tl= ti++)) + { + TABLE *table= tl->table; + + if (tl->is_jtbm()) + continue; + + /* if table will be updated then check that it is unique */ + if (table->map & tables_for_update) + { + if (!tl->single_table_updatable() || check_key_in_view(thd, tl)) + { + my_error(ER_NON_UPDATABLE_TABLE, MYF(0), + tl->top_table()->alias.str, "UPDATE"); + DBUG_RETURN(1); + } + + DBUG_PRINT("info",("setting table `%s` for update", + tl->top_table()->alias.str)); + /* + If table will be updated we should not downgrade lock for it and + leave it as is. + */ + tl->updating= 1; + if (tl->belong_to_view) + tl->belong_to_view->updating= 1; + if (extend_table_list(thd, tl, this, has_prelocking_list)) + DBUG_RETURN(1); + } + else + { + DBUG_PRINT("info",("setting table `%s` for read-only", tl->alias.str)); + /* + If we are using the binary log, we need TL_READ_NO_INSERT to get + correct order of statements. Otherwise, we use a TL_READ lock to + improve performance. + We don't downgrade metadata lock from SW to SR in this case as + there is no guarantee that the same ticket is not used by + another table instance used by this statement which is going to + be write-locked (for example, trigger to be invoked might try + to update this table). + Last argument routine_modifies_data for read_lock_type_for_table() + is ignored, as prelocking placeholder will never be set here. + */ + DBUG_ASSERT(tl->prelocking_placeholder == false); + thr_lock_type lock_type= read_lock_type_for_table(thd, lex, tl, true); + if (using_lock_tables) + tl->lock_type= lock_type; + else + tl->set_lock_type(thd, lock_type); + } + } + + /* + Check access privileges for tables being updated or read. + Note that unlike in the above loop we need to iterate here not only + through all leaf tables but also through all view hierarchy. + */ + + for (tl= table_list; tl; tl= tl->next_local) + { + bool not_used= false; + if (tl->is_jtbm()) + continue; + if (multi_update_check_table_access(thd, tl, tables_for_update, ¬_used)) + DBUG_RETURN(TRUE); + } + + /* check single table update for view compound from several tables */ + for (tl= table_list; tl; tl= tl->next_local) + { + TABLE_LIST *for_update= 0; + if (tl->is_jtbm()) + continue; + if (tl->is_merged_derived() && + tl->check_single_table(&for_update, tables_for_update, tl)) + { + my_error(ER_VIEW_MULTIUPDATE, MYF(0), tl->view_db.str, tl->view_name.str); + DBUG_RETURN(1); + } + } + + DBUG_RETURN(0); +} + +/* + make update specific preparation and checks after opening tables + + SYNOPSIS + mysql_multi_update_prepare() + thd thread handler + + RETURN + FALSE OK + TRUE Error +*/ + +int mysql_multi_update_prepare(THD *thd) +{ + LEX *lex= thd->lex; + TABLE_LIST *table_list= lex->query_tables; + TABLE_LIST *tl; + Multiupdate_prelocking_strategy prelocking_strategy; + uint table_count= lex->table_count; + DBUG_ENTER("mysql_multi_update_prepare"); + + /* + Open tables and create derived ones, but do not lock and fill them yet. + + During prepare phase acquire only S metadata locks instead of SW locks to + keep prepare of multi-UPDATE compatible with concurrent LOCK TABLES WRITE + and global read lock. + + Don't evaluate any subqueries even if constant, because + tables aren't locked yet. + */ + lex->context_analysis_only|= CONTEXT_ANALYSIS_ONLY_DERIVED; + if (thd->lex->sql_command == SQLCOM_UPDATE_MULTI) + { + if (open_tables(thd, &table_list, &table_count, + thd->stmt_arena->is_stmt_prepare() ? MYSQL_OPEN_FORCE_SHARED_MDL : 0, + &prelocking_strategy)) + DBUG_RETURN(TRUE); + } + else + { + /* following need for prepared statements, to run next time multi-update */ + thd->lex->sql_command= SQLCOM_UPDATE_MULTI; + prelocking_strategy.reset(thd); + if (prelocking_strategy.handle_end(thd)) + DBUG_RETURN(TRUE); + } + + /* now lock and fill tables */ + if (!thd->stmt_arena->is_stmt_prepare() && + lock_tables(thd, table_list, table_count, 0)) + DBUG_RETURN(TRUE); + + lex->context_analysis_only&= ~CONTEXT_ANALYSIS_ONLY_DERIVED; + + (void) read_statistics_for_tables_if_needed(thd, table_list); + /* @todo: downgrade the metadata locks here. */ + + /* + Check that we are not using table that we are updating, but we should + skip all tables of UPDATE SELECT itself + */ + lex->first_select_lex()->exclude_from_table_unique_test= TRUE; + /* We only need SELECT privilege for columns in the values list */ + List_iterator<TABLE_LIST> ti(lex->first_select_lex()->leaf_tables); + while ((tl= ti++)) + { + if (tl->is_jtbm()) + continue; + TABLE *table= tl->table; + TABLE_LIST *tlist; + if (!(tlist= tl->top_table())->derived) + { + tlist->grant.want_privilege= + (SELECT_ACL & ~tlist->grant.privilege); + table->grant.want_privilege= (SELECT_ACL & ~table->grant.privilege); + } + DBUG_PRINT("info", ("table: %s want_privilege: %llx", tl->alias.str, + (longlong) table->grant.want_privilege)); + } + /* + Set exclude_from_table_unique_test value back to FALSE. It is needed for + further check in multi_update::prepare whether to use record cache. + */ + lex->first_select_lex()->exclude_from_table_unique_test= FALSE; + + if (lex->save_prep_leaf_tables()) + DBUG_RETURN(TRUE); + + DBUG_RETURN (FALSE); +} + + +/* + Setup multi-update handling and call SELECT to do the join +*/ + +bool mysql_multi_update(THD *thd, TABLE_LIST *table_list, List<Item> *fields, + List<Item> *values, COND *conds, ulonglong options, + enum enum_duplicates handle_duplicates, + bool ignore, SELECT_LEX_UNIT *unit, + SELECT_LEX *select_lex, multi_update **result) +{ + bool res; + DBUG_ENTER("mysql_multi_update"); + + if (!(*result= new (thd->mem_root) multi_update(thd, table_list, + &thd->lex->first_select_lex()->leaf_tables, + fields, values, handle_duplicates, ignore))) + { + DBUG_RETURN(TRUE); + } + + if ((*result)->init(thd)) + DBUG_RETURN(1); + + thd->abort_on_warning= !ignore && thd->is_strict_mode(); + List<Item> total_list; + + if (setup_tables(thd, &select_lex->context, &select_lex->top_join_list, + table_list, select_lex->leaf_tables, FALSE, FALSE)) + DBUG_RETURN(1); + + if (select_lex->vers_setup_conds(thd, table_list)) + DBUG_RETURN(1); + + res= mysql_select(thd, + table_list, total_list, conds, + select_lex->order_list.elements, + select_lex->order_list.first, NULL, NULL, NULL, + options | SELECT_NO_JOIN_CACHE | SELECT_NO_UNLOCK | + OPTION_SETUP_TABLES_DONE, + *result, unit, select_lex); + + DBUG_PRINT("info",("res: %d report_error: %d", res, (int) thd->is_error())); + res|= thd->is_error(); + if (unlikely(res)) + (*result)->abort_result_set(); + else + { + if (thd->lex->describe || thd->lex->analyze_stmt) + res= thd->lex->explain->send_explain(thd); + } + thd->abort_on_warning= 0; + DBUG_RETURN(res); +} + + +multi_update::multi_update(THD *thd_arg, TABLE_LIST *table_list, + List<TABLE_LIST> *leaves_list, + List<Item> *field_list, List<Item> *value_list, + enum enum_duplicates handle_duplicates_arg, + bool ignore_arg): + select_result_interceptor(thd_arg), + all_tables(table_list), leaves(leaves_list), update_tables(0), + tmp_tables(0), updated(0), found(0), fields(field_list), + values(value_list), table_count(0), copy_field(0), + handle_duplicates(handle_duplicates_arg), do_update(1), trans_safe(1), + transactional_tables(0), ignore(ignore_arg), error_handled(0), prepared(0), + updated_sys_ver(0) +{ +} + + +bool multi_update::init(THD *thd) +{ + table_map tables_to_update= get_table_map(fields); + List_iterator_fast<TABLE_LIST> li(*leaves); + TABLE_LIST *tbl; + while ((tbl =li++)) + { + if (tbl->is_jtbm()) + continue; + if (!(tbl->table->map & tables_to_update)) + continue; + if (updated_leaves.push_back(tbl, thd->mem_root)) + return true; + } + return false; +} + + +/* + Connect fields with tables and create list of tables that are updated +*/ + +int multi_update::prepare(List<Item> ¬_used_values, + SELECT_LEX_UNIT *lex_unit) + +{ + TABLE_LIST *table_ref; + SQL_I_List<TABLE_LIST> update; + table_map tables_to_update; + Item_field *item; + List_iterator_fast<Item> field_it(*fields); + List_iterator_fast<Item> value_it(*values); + uint i, max_fields; + uint leaf_table_count= 0; + List_iterator<TABLE_LIST> ti(updated_leaves); + DBUG_ENTER("multi_update::prepare"); + + if (prepared) + DBUG_RETURN(0); + prepared= true; + + thd->count_cuted_fields= CHECK_FIELD_WARN; + thd->cuted_fields=0L; + THD_STAGE_INFO(thd, stage_updating_main_table); + + tables_to_update= get_table_map(fields); + + if (!tables_to_update) + { + my_message(ER_NO_TABLES_USED, ER_THD(thd, ER_NO_TABLES_USED), MYF(0)); + DBUG_RETURN(1); + } + + /* + We gather the set of columns read during evaluation of SET expression in + TABLE::tmp_set by pointing TABLE::read_set to it and then restore it after + setup_fields(). + */ + while ((table_ref= ti++)) + { + if (table_ref->is_jtbm()) + continue; + + TABLE *table= table_ref->table; + if (tables_to_update & table->map) + { + DBUG_ASSERT(table->read_set == &table->def_read_set); + table->read_set= &table->tmp_set; + bitmap_clear_all(table->read_set); + } + } + + /* + We have to check values after setup_tables to get covering_keys right in + reference tables + */ + + int error= setup_fields(thd, Ref_ptr_array(), + *values, MARK_COLUMNS_READ, 0, NULL, 0); + + ti.rewind(); + while ((table_ref= ti++)) + { + if (table_ref->is_jtbm()) + continue; + + TABLE *table= table_ref->table; + if (tables_to_update & table->map) + { + table->read_set= &table->def_read_set; + bitmap_union(table->read_set, &table->tmp_set); + table->file->prepare_for_insert(1); + } + } + if (unlikely(error)) + DBUG_RETURN(1); + + /* + Save tables being updated in update_tables + update_table->shared is position for table + Don't use key read on tables that are updated + */ + + update.empty(); + ti.rewind(); + while ((table_ref= ti++)) + { + /* TODO: add support of view of join support */ + if (table_ref->is_jtbm()) + continue; + TABLE *table=table_ref->table; + leaf_table_count++; + if (tables_to_update & table->map) + { + TABLE_LIST *tl= (TABLE_LIST*) thd->memdup(table_ref, + sizeof(*tl)); + if (!tl) + DBUG_RETURN(1); + update.link_in_list(tl, &tl->next_local); + tl->shared= table_count++; + table->no_keyread=1; + table->covering_keys.clear_all(); + table->pos_in_table_list= tl; + table->prepare_triggers_for_update_stmt_or_event(); + table->reset_default_fields(); + } + } + + table_count= update.elements; + update_tables= update.first; + + tmp_tables = (TABLE**) thd->calloc(sizeof(TABLE *) * table_count); + tmp_table_param = (TMP_TABLE_PARAM*) thd->calloc(sizeof(TMP_TABLE_PARAM) * + table_count); + fields_for_table= (List_item **) thd->alloc(sizeof(List_item *) * + table_count); + values_for_table= (List_item **) thd->alloc(sizeof(List_item *) * + table_count); + if (unlikely(thd->is_fatal_error)) + DBUG_RETURN(1); + for (i=0 ; i < table_count ; i++) + { + fields_for_table[i]= new List_item; + values_for_table[i]= new List_item; + } + if (unlikely(thd->is_fatal_error)) + DBUG_RETURN(1); + + /* Split fields into fields_for_table[] and values_by_table[] */ + + while ((item= (Item_field *) field_it++)) + { + Item *value= value_it++; + uint offset= item->field->table->pos_in_table_list->shared; + fields_for_table[offset]->push_back(item, thd->mem_root); + values_for_table[offset]->push_back(value, thd->mem_root); + } + if (unlikely(thd->is_fatal_error)) + DBUG_RETURN(1); + + /* Allocate copy fields */ + max_fields=0; + for (i=0 ; i < table_count ; i++) + { + set_if_bigger(max_fields, fields_for_table[i]->elements + leaf_table_count); + if (fields_for_table[i]->elements) + { + TABLE *table= ((Item_field*)(fields_for_table[i]->head()))->field->table; + switch_to_nullable_trigger_fields(*fields_for_table[i], table); + switch_to_nullable_trigger_fields(*values_for_table[i], table); + } + } + copy_field= new (thd->mem_root) Copy_field[max_fields]; + DBUG_RETURN(thd->is_fatal_error != 0); +} + +void multi_update::update_used_tables() +{ + Item *item; + List_iterator_fast<Item> it(*values); + while ((item= it++)) + { + item->update_used_tables(); + } +} + +void multi_update::prepare_to_read_rows() +{ + /* + update column maps now. it cannot be done in ::prepare() before the + optimizer, because the optimize might reset them (in + SELECT_LEX::update_used_tables()), it cannot be done in + ::initialize_tables() after the optimizer, because the optimizer + might read rows from const tables + */ + + for (TABLE_LIST *tl= update_tables; tl; tl= tl->next_local) + tl->table->mark_columns_needed_for_update(); +} + + +/* + Check if table is safe to update on fly + + SYNOPSIS + safe_update_on_fly() + thd Thread handler + join_tab How table is used in join + all_tables List of tables + + NOTES + We can update the first table in join on the fly if we know that + a row in this table will never be read twice. This is true under + the following conditions: + + - No column is both written to and read in SET expressions. + + - We are doing a table scan and the data is in a separate file (MyISAM) or + if we don't update a clustered key. + + - We are doing a range scan and we don't update the scan key or + the primary key for a clustered table handler. + + - Table is not joined to itself. + + This function gets information about fields to be updated from + the TABLE::write_set bitmap. + + WARNING + This code is a bit dependent of how make_join_readinfo() works. + + The field table->tmp_set is used for keeping track of which fields are + read during evaluation of the SET expression. See multi_update::prepare. + + RETURN + 0 Not safe to update + 1 Safe to update +*/ + +static bool safe_update_on_fly(THD *thd, JOIN_TAB *join_tab, + TABLE_LIST *table_ref, TABLE_LIST *all_tables) +{ + TABLE *table= join_tab->table; + if (unique_table(thd, table_ref, all_tables, 0)) + return 0; + if (join_tab->join->order) // FIXME this is probably too strong + return 0; + switch (join_tab->type) { + case JT_SYSTEM: + case JT_CONST: + case JT_EQ_REF: + return TRUE; // At most one matching row + case JT_REF: + case JT_REF_OR_NULL: + return !is_key_used(table, join_tab->ref.key, table->write_set); + case JT_ALL: + if (bitmap_is_overlapping(&table->tmp_set, table->write_set)) + return FALSE; + /* If range search on index */ + if (join_tab->quick) + return !join_tab->quick->is_keys_used(table->write_set); + /* If scanning in clustered key */ + if ((table->file->ha_table_flags() & HA_PRIMARY_KEY_IN_READ_INDEX) && + table->s->primary_key < MAX_KEY) + return !is_key_used(table, table->s->primary_key, table->write_set); + return TRUE; + default: + break; // Avoid compiler warning + } + return FALSE; + +} + + +/* + Initialize table for multi table + + IMPLEMENTATION + - Update first table in join on the fly, if possible + - Create temporary tables to store changed values for all other tables + that are updated (and main_table if the above doesn't hold). +*/ + +bool +multi_update::initialize_tables(JOIN *join) +{ + TABLE_LIST *table_ref; + DBUG_ENTER("initialize_tables"); + + if (unlikely((thd->variables.option_bits & OPTION_SAFE_UPDATES) && + error_if_full_join(join))) + DBUG_RETURN(1); + main_table=join->join_tab->table; + table_to_update= 0; + + /* Any update has at least one pair (field, value) */ + DBUG_ASSERT(fields->elements); + /* + Only one table may be modified by UPDATE of an updatable view. + For an updatable view first_table_for_update indicates this + table. + For a regular multi-update it refers to some updated table. + */ + TABLE *first_table_for_update= ((Item_field *) fields->head())->field->table; + + /* Create a temporary table for keys to all tables, except main table */ + for (table_ref= update_tables; table_ref; table_ref= table_ref->next_local) + { + TABLE *table=table_ref->table; + uint cnt= table_ref->shared; + List<Item> temp_fields; + ORDER group; + TMP_TABLE_PARAM *tmp_param; + + if (ignore) + table->file->extra(HA_EXTRA_IGNORE_DUP_KEY); + if (table == main_table) // First table in join + { + if (safe_update_on_fly(thd, join->join_tab, table_ref, all_tables)) + { + table_to_update= table; // Update table on the fly + has_vers_fields= table->vers_check_update(*fields); + continue; + } + } + table->prepare_for_position(); + join->map2table[table->tablenr]->keep_current_rowid= true; + + /* + enable uncacheable flag if we update a view with check option + and check option has a subselect, otherwise, the check option + can be evaluated after the subselect was freed as independent + (See full_local in JOIN::join_free()). + */ + if (table_ref->check_option && !join->select_lex->uncacheable) + { + SELECT_LEX_UNIT *tmp_unit; + SELECT_LEX *sl; + for (tmp_unit= join->select_lex->first_inner_unit(); + tmp_unit; + tmp_unit= tmp_unit->next_unit()) + { + for (sl= tmp_unit->first_select(); sl; sl= sl->next_select()) + { + if (sl->master_unit()->item) + { + join->select_lex->uncacheable|= UNCACHEABLE_CHECKOPTION; + goto loop_end; + } + } + } + } +loop_end: + + if (table == first_table_for_update && table_ref->check_option) + { + table_map unupdated_tables= table_ref->check_option->used_tables() & + ~first_table_for_update->map; + List_iterator<TABLE_LIST> ti(*leaves); + TABLE_LIST *tbl_ref; + while ((tbl_ref= ti++) && unupdated_tables) + { + if (unupdated_tables & tbl_ref->table->map) + unupdated_tables&= ~tbl_ref->table->map; + else + continue; + if (unupdated_check_opt_tables.push_back(tbl_ref->table)) + DBUG_RETURN(1); + } + } + + tmp_param= tmp_table_param+cnt; + + /* + Create a temporary table to store all fields that are changed for this + table. The first field in the temporary table is a pointer to the + original row so that we can find and update it. For the updatable + VIEW a few following fields are rowids of tables used in the CHECK + OPTION condition. + */ + + List_iterator_fast<TABLE> tbl_it(unupdated_check_opt_tables); + TABLE *tbl= table; + do + { + LEX_CSTRING field_name; + field_name.str= tbl->alias.c_ptr(); + field_name.length= strlen(field_name.str); + /* + Signal each table (including tables referenced by WITH CHECK OPTION + clause) for which we will store row position in the temporary table + that we need a position to be read first. + */ + tbl->prepare_for_position(); + join->map2table[tbl->tablenr]->keep_current_rowid= true; + + Item_temptable_rowid *item= + new (thd->mem_root) Item_temptable_rowid(tbl); + if (!item) + DBUG_RETURN(1); + item->fix_fields(thd, 0); + if (temp_fields.push_back(item, thd->mem_root)) + DBUG_RETURN(1); + } while ((tbl= tbl_it++)); + + temp_fields.append(fields_for_table[cnt]); + + /* Make an unique key over the first field to avoid duplicated updates */ + bzero((char*) &group, sizeof(group)); + group.direction= ORDER::ORDER_ASC; + group.item= (Item**) temp_fields.head_ref(); + + tmp_param->quick_group= 1; + tmp_param->field_count= temp_fields.elements; + tmp_param->func_count= temp_fields.elements - 1; + calc_group_buffer(tmp_param, &group); + /* small table, ignore @@big_tables */ + my_bool save_big_tables= thd->variables.big_tables; + thd->variables.big_tables= FALSE; + tmp_tables[cnt]=create_tmp_table(thd, tmp_param, temp_fields, + (ORDER*) &group, 0, 0, + TMP_TABLE_ALL_COLUMNS, HA_POS_ERROR, &empty_clex_str); + thd->variables.big_tables= save_big_tables; + if (!tmp_tables[cnt]) + DBUG_RETURN(1); + tmp_tables[cnt]->file->extra(HA_EXTRA_WRITE_CACHE); + } + join->tmp_table_keep_current_rowid= TRUE; + DBUG_RETURN(0); +} + + +static TABLE *item_rowid_table(Item *item) +{ + if (item->type() != Item::FUNC_ITEM) + return NULL; + Item_func *func= (Item_func *)item; + if (func->functype() != Item_func::TEMPTABLE_ROWID) + return NULL; + Item_temptable_rowid *itr= (Item_temptable_rowid *)func; + return itr->table; +} + + +/* + multi_update stores a rowid and new field values for every updated row in a + temporary table (one temporary table per updated table). These rowids are + obtained via Item_temptable_rowid's by calling handler::position(). But if + the join is resolved via a temp table, rowids cannot be obtained from + handler::position() in the multi_update::send_data(). So, they're stored in + the join's temp table (JOIN::add_fields_for_current_rowid()) and here we + replace Item_temptable_rowid's (that would've done handler::position()) with + Item_field's (that will simply take the corresponding field value from the + temp table). +*/ +int multi_update::prepare2(JOIN *join) +{ + if (!join->need_tmp || !join->tmp_table_keep_current_rowid) + return 0; + + // there cannot be many tmp tables in multi-update + JOIN_TAB *tmptab= join->join_tab + join->exec_join_tab_cnt(); + + for (Item **it= tmptab->tmp_table_param->items_to_copy; *it ; it++) + { + TABLE *tbl= item_rowid_table(*it); + if (!tbl) + continue; + for (uint i= 0; i < table_count; i++) + { + for (Item **it2= tmp_table_param[i].items_to_copy; *it2; it2++) + { + if (item_rowid_table(*it2) != tbl) + continue; + Item_field *fld= new (thd->mem_root) + Item_field(thd, (*it)->get_tmp_table_field()); + if (!fld) + return 1; + fld->result_field= (*it2)->get_tmp_table_field(); + *it2= fld; + } + } + } + return 0; +} + + +multi_update::~multi_update() +{ + TABLE_LIST *table; + for (table= update_tables ; table; table= table->next_local) + { + table->table->no_keyread= 0; + if (ignore) + table->table->file->extra(HA_EXTRA_NO_IGNORE_DUP_KEY); + } + + if (tmp_tables) + { + for (uint cnt = 0; cnt < table_count; cnt++) + { + if (tmp_tables[cnt]) + { + free_tmp_table(thd, tmp_tables[cnt]); + tmp_table_param[cnt].cleanup(); + } + } + } + if (copy_field) + delete [] copy_field; + thd->count_cuted_fields= CHECK_FIELD_IGNORE; // Restore this setting + DBUG_ASSERT(trans_safe || !updated || + thd->transaction->all.modified_non_trans_table); +} + + +int multi_update::send_data(List<Item> ¬_used_values) +{ + TABLE_LIST *cur_table; + DBUG_ENTER("multi_update::send_data"); + + for (cur_table= update_tables; cur_table; cur_table= cur_table->next_local) + { + int error= 0; + TABLE *table= cur_table->table; + uint offset= cur_table->shared; + /* + Check if we are using outer join and we didn't find the row + or if we have already updated this row in the previous call to this + function. + + The same row may be presented here several times in a join of type + UPDATE t1 FROM t1,t2 SET t1.a=t2.a + + In this case we will do the update for the first found row combination. + The join algorithm guarantees that we will not find the a row in + t1 several times. + */ + if (table->status & (STATUS_NULL_ROW | STATUS_UPDATED)) + continue; + + if (table == table_to_update) + { + /* + We can use compare_record() to optimize away updates if + the table handler is returning all columns OR if + if all updated columns are read + */ + bool can_compare_record; + can_compare_record= records_are_comparable(table); + + table->status|= STATUS_UPDATED; + store_record(table,record[1]); + + if (fill_record_n_invoke_before_triggers(thd, table, + *fields_for_table[offset], + *values_for_table[offset], 0, + TRG_EVENT_UPDATE)) + DBUG_RETURN(1); + /* + Reset the table->auto_increment_field_not_null as it is valid for + only one row. + */ + table->auto_increment_field_not_null= FALSE; + found++; + if (!can_compare_record || compare_record(table)) + { + + if ((error= cur_table->view_check_option(thd, ignore)) != + VIEW_CHECK_OK) + { + found--; + if (error == VIEW_CHECK_SKIP) + continue; + else if (unlikely(error == VIEW_CHECK_ERROR)) + DBUG_RETURN(1); + } + if (unlikely(!updated++)) + { + /* + Inform the main table that we are going to update the table even + while we may be scanning it. This will flush the read cache + if it's used. + */ + main_table->file->extra(HA_EXTRA_PREPARE_FOR_UPDATE); + } + if (unlikely((error=table->file->ha_update_row(table->record[1], + table->record[0]))) && + error != HA_ERR_RECORD_IS_THE_SAME) + { + updated--; + if (!ignore || + table->file->is_fatal_error(error, HA_CHECK_ALL)) + goto error; + } + else + { + if (unlikely(error == HA_ERR_RECORD_IS_THE_SAME)) + { + error= 0; + updated--; + } + else if (has_vers_fields && table->versioned(VERS_TRX_ID)) + { + updated_sys_ver++; + } + /* non-transactional or transactional table got modified */ + /* either multi_update class' flag is raised in its branch */ + if (table->file->has_transactions_and_rollback()) + transactional_tables= TRUE; + else + { + trans_safe= FALSE; + thd->transaction->stmt.modified_non_trans_table= TRUE; + } + } + } + if (has_vers_fields && table->versioned(VERS_TIMESTAMP)) + { + store_record(table, record[2]); + if (unlikely(error= vers_insert_history_row(table))) + { + restore_record(table, record[2]); + goto error; + } + restore_record(table, record[2]); + updated_sys_ver++; + } + if (table->triggers && + unlikely(table->triggers->process_triggers(thd, TRG_EVENT_UPDATE, + TRG_ACTION_AFTER, TRUE))) + DBUG_RETURN(1); + } + else + { + TABLE *tmp_table= tmp_tables[offset]; + if (copy_funcs(tmp_table_param[offset].items_to_copy, thd)) + DBUG_RETURN(1); + /* rowid field is NULL if join tmp table has null row from outer join */ + if (tmp_table->field[0]->is_null()) + continue; + /* Store regular updated fields in the row. */ + DBUG_ASSERT(1 + unupdated_check_opt_tables.elements == + tmp_table_param[offset].func_count); + fill_record(thd, tmp_table, + tmp_table->field + 1 + unupdated_check_opt_tables.elements, + *values_for_table[offset], TRUE, FALSE); + + /* Write row, ignoring duplicated updates to a row */ + error= tmp_table->file->ha_write_tmp_row(tmp_table->record[0]); + found++; + if (unlikely(error)) + { + found--; + if (error != HA_ERR_FOUND_DUPP_KEY && + error != HA_ERR_FOUND_DUPP_UNIQUE) + { + if (create_internal_tmp_table_from_heap(thd, tmp_table, + tmp_table_param[offset].start_recinfo, + &tmp_table_param[offset].recinfo, + error, 1, NULL)) + { + do_update= 0; + DBUG_RETURN(1); // Not a table_is_full error + } + found++; + } + } + } + continue; +error: + DBUG_ASSERT(error > 0); + /* + If (ignore && error == is ignorable) we don't have to + do anything; otherwise... + */ + myf flags= 0; + + if (table->file->is_fatal_error(error, HA_CHECK_ALL)) + flags|= ME_FATAL; /* Other handler errors are fatal */ + + prepare_record_for_error_message(error, table); + table->file->print_error(error,MYF(flags)); + DBUG_RETURN(1); + } // for (cur_table) + DBUG_RETURN(0); +} + + +void multi_update::abort_result_set() +{ + /* the error was handled or nothing deleted and no side effects return */ + if (unlikely(error_handled || + (!thd->transaction->stmt.modified_non_trans_table && !updated))) + return; + + /* Something already updated so we have to invalidate cache */ + if (updated) + query_cache_invalidate3(thd, update_tables, 1); + /* + If all tables that has been updated are trans safe then just do rollback. + If not attempt to do remaining updates. + */ + + if (! trans_safe) + { + DBUG_ASSERT(thd->transaction->stmt.modified_non_trans_table); + if (do_update && table_count > 1) + { + /* Add warning here */ + (void) do_updates(); + } + } + if (thd->transaction->stmt.modified_non_trans_table) + { + /* + The query has to binlog because there's a modified non-transactional table + either from the query's list or via a stored routine: bug#13270,23333 + */ + if (WSREP_EMULATE_BINLOG(thd) || mysql_bin_log.is_open()) + { + /* + THD::killed status might not have been set ON at time of an error + got caught and if happens later the killed error is written + into repl event. + */ + int errcode= query_error_code(thd, thd->killed == NOT_KILLED); + /* the error of binary logging is ignored */ + (void)thd->binlog_query(THD::ROW_QUERY_TYPE, + thd->query(), thd->query_length(), + transactional_tables, FALSE, FALSE, errcode); + } + thd->transaction->all.modified_non_trans_table= TRUE; + } + thd->transaction->all.m_unsafe_rollback_flags|= + (thd->transaction->stmt.m_unsafe_rollback_flags & THD_TRANS::DID_WAIT); + DBUG_ASSERT(trans_safe || !updated || thd->transaction->stmt.modified_non_trans_table); +} + + +int multi_update::do_updates() +{ + TABLE_LIST *cur_table; + int local_error= 0; + ha_rows org_updated; + TABLE *table, *tmp_table, *err_table; + List_iterator_fast<TABLE> check_opt_it(unupdated_check_opt_tables); + DBUG_ENTER("multi_update::do_updates"); + + do_update= 0; // Don't retry this function + if (!found) + DBUG_RETURN(0); + + /* + Update read_set to include all fields that virtual columns may depend on. + Usually they're already in the read_set, but if the previous access + method was keyread, only the virtual column itself will be in read_set, + not its dependencies + */ + while(TABLE *tbl= check_opt_it++) + if (Field **vf= tbl->vfield) + for (; *vf; vf++) + if (bitmap_is_set(tbl->read_set, (*vf)->field_index)) + (*vf)->vcol_info->expr->walk(&Item::register_field_in_read_map, 1, 0); + + for (cur_table= update_tables; cur_table; cur_table= cur_table->next_local) + { + bool can_compare_record; + uint offset= cur_table->shared; + + table = cur_table->table; + if (table == table_to_update) + continue; // Already updated + org_updated= updated; + tmp_table= tmp_tables[cur_table->shared]; + tmp_table->file->extra(HA_EXTRA_CACHE); // Change to read cache + if (unlikely((local_error= table->file->ha_rnd_init(0)))) + { + err_table= table; + goto err; + } + table->file->extra(HA_EXTRA_NO_CACHE); + /* + We have to clear the base record, if we have virtual indexed + blob fields, as some storage engines will access the blob fields + to calculate the keys to see if they have changed. Without + clearing the blob pointers will contain random values which can + cause a crash. + This is a workaround for engines that access columns not present in + either read or write set. + */ + if (table->vfield) + empty_record(table); + + has_vers_fields= table->vers_check_update(*fields); + + check_opt_it.rewind(); + while(TABLE *tbl= check_opt_it++) + { + if (unlikely((local_error= tbl->file->ha_rnd_init(0)))) + { + err_table= tbl; + goto err; + } + tbl->file->extra(HA_EXTRA_CACHE); + } + + /* + Setup copy functions to copy fields from temporary table + */ + List_iterator_fast<Item> field_it(*fields_for_table[offset]); + Field **field; + Copy_field *copy_field_ptr= copy_field, *copy_field_end; + + /* Skip row pointers */ + field= tmp_table->field + 1 + unupdated_check_opt_tables.elements; + for ( ; *field ; field++) + { + Item_field *item= (Item_field* ) field_it++; + (copy_field_ptr++)->set(item->field, *field, 0); + } + copy_field_end=copy_field_ptr; + + if (unlikely((local_error= tmp_table->file->ha_rnd_init(1)))) + { + err_table= tmp_table; + goto err; + } + + can_compare_record= records_are_comparable(table); + + for (;;) + { + if (thd->killed && trans_safe) + { + thd->fatal_error(); + goto err2; + } + if (unlikely((local_error= + tmp_table->file->ha_rnd_next(tmp_table->record[0])))) + { + if (local_error == HA_ERR_END_OF_FILE) + break; + err_table= tmp_table; + goto err; + } + + /* call rnd_pos() using rowids from temporary table */ + check_opt_it.rewind(); + TABLE *tbl= table; + uint field_num= 0; + do + { + DBUG_ASSERT(!tmp_table->field[field_num]->is_null()); + String rowid; + tmp_table->field[field_num]->val_str(&rowid); + if (unlikely((local_error= tbl->file->ha_rnd_pos(tbl->record[0], + (uchar*)rowid.ptr())))) + { + err_table= tbl; + goto err; + } + field_num++; + } while ((tbl= check_opt_it++)); + + if (table->vfield && + unlikely(table->update_virtual_fields(table->file, + VCOL_UPDATE_INDEXED_FOR_UPDATE))) + goto err2; + + table->status|= STATUS_UPDATED; + store_record(table,record[1]); + + /* Copy data from temporary table to current table */ + for (copy_field_ptr=copy_field; + copy_field_ptr != copy_field_end; + copy_field_ptr++) + { + (*copy_field_ptr->do_copy)(copy_field_ptr); + copy_field_ptr->to_field->set_has_explicit_value(); + } + + table->evaluate_update_default_function(); + if (table->vfield && + table->update_virtual_fields(table->file, VCOL_UPDATE_FOR_WRITE)) + goto err2; + if (table->triggers && + table->triggers->process_triggers(thd, TRG_EVENT_UPDATE, + TRG_ACTION_BEFORE, TRUE)) + goto err2; + + if (!can_compare_record || compare_record(table)) + { + int error; + if ((error= cur_table->view_check_option(thd, ignore)) != + VIEW_CHECK_OK) + { + if (error == VIEW_CHECK_SKIP) + continue; + else if (unlikely(error == VIEW_CHECK_ERROR)) + { + thd->fatal_error(); + goto err2; + } + } + if (has_vers_fields && table->versioned()) + table->vers_update_fields(); + + if (unlikely((local_error= + table->file->ha_update_row(table->record[1], + table->record[0]))) && + local_error != HA_ERR_RECORD_IS_THE_SAME) + { + if (!ignore || + table->file->is_fatal_error(local_error, HA_CHECK_ALL)) + { + err_table= table; + goto err; + } + } + if (local_error != HA_ERR_RECORD_IS_THE_SAME) + { + updated++; + + if (has_vers_fields && table->versioned()) + { + if (table->versioned(VERS_TIMESTAMP)) + { + store_record(table, record[2]); + if ((local_error= vers_insert_history_row(table))) + { + restore_record(table, record[2]); + err_table = table; + goto err; + } + restore_record(table, record[2]); + } + updated_sys_ver++; + } + } + else + local_error= 0; + } + + if (table->triggers && + unlikely(table->triggers->process_triggers(thd, TRG_EVENT_UPDATE, + TRG_ACTION_AFTER, TRUE))) + goto err2; + } + + if (updated != org_updated) + { + if (table->file->has_transactions_and_rollback()) + transactional_tables= TRUE; + else + { + trans_safe= FALSE; // Can't do safe rollback + thd->transaction->stmt.modified_non_trans_table= TRUE; + } + } + (void) table->file->ha_rnd_end(); + (void) tmp_table->file->ha_rnd_end(); + check_opt_it.rewind(); + while (TABLE *tbl= check_opt_it++) + tbl->file->ha_rnd_end(); + + } + DBUG_RETURN(0); + +err: + { + prepare_record_for_error_message(local_error, err_table); + err_table->file->print_error(local_error,MYF(ME_FATAL)); + } + +err2: + if (table->file->inited) + (void) table->file->ha_rnd_end(); + if (tmp_table->file->inited) + (void) tmp_table->file->ha_rnd_end(); + check_opt_it.rewind(); + while (TABLE *tbl= check_opt_it++) + { + if (tbl->file->inited) + (void) tbl->file->ha_rnd_end(); + } + + if (updated != org_updated) + { + if (table->file->has_transactions_and_rollback()) + transactional_tables= TRUE; + else + { + trans_safe= FALSE; + thd->transaction->stmt.modified_non_trans_table= TRUE; + } + } + DBUG_RETURN(1); +} + + +/* out: 1 if error, 0 if success */ + +bool multi_update::send_eof() +{ + char buff[STRING_BUFFER_USUAL_SIZE]; + ulonglong id; + killed_state killed_status= NOT_KILLED; + DBUG_ENTER("multi_update::send_eof"); + THD_STAGE_INFO(thd, stage_updating_reference_tables); + + /* + Does updates for the last n - 1 tables, returns 0 if ok; + error takes into account killed status gained in do_updates() + */ + int local_error= thd->is_error(); + if (likely(!local_error)) + local_error = (table_count) ? do_updates() : 0; + /* + if local_error is not set ON until after do_updates() then + later carried out killing should not affect binlogging. + */ + killed_status= (local_error == 0) ? NOT_KILLED : thd->killed; + THD_STAGE_INFO(thd, stage_end); + + /* We must invalidate the query cache before binlog writing and + ha_autocommit_... */ + + if (updated) + { + query_cache_invalidate3(thd, update_tables, 1); + } + /* + Write the SQL statement to the binlog if we updated + rows and we succeeded or if we updated some non + transactional tables. + + The query has to binlog because there's a modified non-transactional table + either from the query's list or via a stored routine: bug#13270,23333 + */ + + if (thd->transaction->stmt.modified_non_trans_table) + thd->transaction->all.modified_non_trans_table= TRUE; + thd->transaction->all.m_unsafe_rollback_flags|= + (thd->transaction->stmt.m_unsafe_rollback_flags & THD_TRANS::DID_WAIT); + + if (likely(local_error == 0 || + thd->transaction->stmt.modified_non_trans_table)) + { + if (WSREP_EMULATE_BINLOG(thd) || mysql_bin_log.is_open()) + { + int errcode= 0; + if (likely(local_error == 0)) + thd->clear_error(); + else + errcode= query_error_code(thd, killed_status == NOT_KILLED); + + bool force_stmt= false; + for (TABLE *table= all_tables->table; table; table= table->next) + { + if (table->versioned(VERS_TRX_ID)) + { + force_stmt= true; + break; + } + } + enum_binlog_format save_binlog_format; + save_binlog_format= thd->get_current_stmt_binlog_format(); + if (force_stmt) + thd->set_current_stmt_binlog_format_stmt(); + + if (thd->binlog_query(THD::ROW_QUERY_TYPE, thd->query(), + thd->query_length(), transactional_tables, FALSE, + FALSE, errcode) > 0) + local_error= 1; // Rollback update + thd->set_current_stmt_binlog_format(save_binlog_format); + } + } + DBUG_ASSERT(trans_safe || !updated || + thd->transaction->stmt.modified_non_trans_table); + + if (unlikely(local_error)) + { + error_handled= TRUE; // to force early leave from ::abort_result_set() + if (thd->killed == NOT_KILLED && !thd->get_stmt_da()->is_set()) + { + /* + No error message was sent and query was not killed (in which case + mysql_execute_command() will send the error mesage). + */ + my_message(ER_UNKNOWN_ERROR, "An error occurred in multi-table update", + MYF(0)); + } + DBUG_RETURN(TRUE); + } + + if (!thd->lex->analyze_stmt) + { + id= thd->arg_of_last_insert_id_function ? + thd->first_successful_insert_id_in_prev_stmt : 0; + my_snprintf(buff, sizeof(buff), ER_THD(thd, ER_UPDATE_INFO), + (ulong) found, (ulong) updated, (ulong) thd->cuted_fields); + ::my_ok(thd, (thd->client_capabilities & CLIENT_FOUND_ROWS) ? found : updated, + id, buff); + } + DBUG_RETURN(FALSE); +} |