/* Copyright (c) 2000, 2016, Oracle and/or its affiliates. Copyright (c) 2011, 2016, 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 02110-1301 USA */ /* Single table and multi table updates of tables. Multi-table updates were introduced by Sinisa & Monty */ #include /* 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 "sql_acl.h" // *_ACL, check_grant #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 /** 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->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) != 0) { /* 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. */ for (Field **ptr= table->field ; *ptr != NULL; ptr++) { Field *field= *ptr; if (bitmap_is_set(table->write_set, field->field_index)) { if (field->real_maybe_null()) { uchar null_byte_index= 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++) { if (bitmap_is_set(table->write_set, (*ptr)->field_index) && (*ptr)->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, List &items) { List_iterator it(items); Item *item; 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); 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 Item_field(thd, field)); } 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 ((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_columns_used_by_index_no_reset(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(); /* 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; } /* 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 handle_duplicates how to handle duplicates 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 &fields, List &values, COND *conds, uint order_num, ORDER *order, ha_rows limit, enum enum_duplicates handle_duplicates, bool ignore, ha_rows *found_return, ha_rows *updated_return) { bool using_limit= limit != HA_POS_ERROR; bool safe_update= MY_TEST(thd->variables.option_bits & OPTION_SAFE_UPDATES); bool used_key_is_modified= FALSE, transactional_table, will_batch; bool can_compare_record; int res; int error, loc_error; uint dup_key_found; bool need_sort= TRUE; bool reverse= FALSE; #ifndef NO_EMBEDDED_ACCESS_CHECKS uint want_privilege; #endif uint table_count= 0; ha_rows updated, found; key_map old_covering_keys; TABLE *table; SQL_SELECT *select= NULL; READ_RECORD info; SELECT_LEX *select_lex= &thd->lex->select_lex; ulonglong id; List all_fields; killed_state killed_status= NOT_KILLED; Update_plan query_plan(thd->mem_root); query_plan.index= MAX_KEY; query_plan.using_filesort= FALSE; 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->is_multitable()) { DBUG_ASSERT(table_list->view != 0); DBUG_PRINT("info", ("Switch to multi-update")); /* pass counter value */ thd->lex->table_count= table_count; /* convert to multiupdate */ DBUG_RETURN(2); } if (lock_tables(thd, table_list, table_count, 0)) DBUG_RETURN(1); 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); THD_STAGE_INFO(thd, stage_init); table= table_list->table; if (!table_list->single_table_updatable()) { my_error(ER_NON_UPDATABLE_TABLE, MYF(0), table_list->alias, "UPDATE"); DBUG_RETURN(1); } query_plan.updating_a_view= MY_TEST(table_list->view); /* Calculate "table->covering_keys" based on the WHERE */ table->covering_keys= table->s->keys_in_use; table->quick_keys.clear_all(); query_plan.select_lex= &thd->lex->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 if (mysql_prepare_update(thd, table_list, &conds, order_num, order)) DBUG_RETURN(1); 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, 0, fields, MARK_COLUMNS_WRITE, 0, 0)) DBUG_RETURN(1); /* purecov: inspected */ if (table_list->view && check_fields(thd, fields)) { DBUG_RETURN(1); } if (check_key_in_view(thd, table_list)) { my_error(ER_NON_UPDATABLE_TABLE, MYF(0), table_list->alias, "UPDATE"); DBUG_RETURN(1); } if (table->default_field) table->mark_default_fields_for_write(); #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, 0, 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); /* 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= remove_eq_conds(thd, conds, &cond_value); if (cond_value == Item::COND_FALSE) { limit= 0; // Impossible WHERE query_plan.set_impossible_where(); if (thd->lex->describe) goto exit_without_my_ok; } } /* If a timestamp field settable on UPDATE is present then to avoid wrong update force the table handler to retrieve write-only fields to be able to compare records and detect data change. */ if ((table->file->ha_table_flags() & HA_PARTIAL_COLUMN_READ) && table->default_field && table->has_default_function(true)) bitmap_union(table->read_set, table->write_set); // 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) goto exit_without_my_ok; 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, 0, &error); if (error || !limit || thd->is_error() || (select && select->check_quick(thd, safe_update, limit))) { query_plan.set_impossible_where(); if (thd->lex->describe) goto exit_without_my_ok; 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->quick_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(ER_UPDATE_WITHOUT_KEY_IN_SAFE_MODE), MYF(0)); goto err; } } init_ftfuncs(thd, select_lex, 1); 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; query_plan.index= get_index_for_order(order, table, select, limit, &scanned_limit, &need_sort, &reverse); 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 exit_without_my_ok; query_plan.save_explain_data(thd->lex->explain); DBUG_EXECUTE_IF("show_explain_probe_update_exec_start", dbug_serve_apcs(thd, 1);); if (!(select && select->quick)) status_var_increment(thd->status_var.update_scan_count); 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! */ 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->add_read_columns_used_by_index(query_plan.index); else table->use_all_columns(); /* 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() */ uint length= 0; SORT_FIELD *sortorder; ha_rows examined_rows; ha_rows found_rows; table->sort.io_cache = (IO_CACHE *) my_malloc(sizeof(IO_CACHE), MYF(MY_FAE | MY_ZEROFILL | MY_THREAD_SPECIFIC)); if (!(sortorder=make_unireg_sortorder(order, &length, NULL)) || (table->sort.found_records= filesort(thd, table, sortorder, length, select, limit, true, &examined_rows, &found_rows)) == HA_POS_ERROR) { goto err; } thd->inc_examined_row_count(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 { /* 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. */ 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, 0, 1, FALSE); else error= init_read_record_idx(&info, thd, table, 1, query_plan.index, reverse); if (error) { close_cached_file(&tempfile); goto err; } THD_STAGE_INFO(thd, stage_searching_rows_for_update); ha_rows tmp_limit= limit; while (!(error=info.read_record(&info)) && !thd->killed) { if (table->vfield) update_virtual_fields(thd, table, VCOL_UPDATE_FOR_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 */ table->file->position(table->record[0]); if (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 (error < 0) { /* Fatal error from select->skip_record() */ error= 1; break; } else table->file->unlock_row(); } } if (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 { select= new SQL_SELECT; select->head=table; } //psergey-todo: disable SHOW EXPLAIN because the plan was deleted? if (reinit_io_cache(&tempfile,READ_CACHE,0L,0,0)) error=1; /* purecov: inspected */ select->file=tempfile; // Read row ptrs from this file if (error >= 0) goto err; } table->disable_keyread(); table->column_bitmaps_set(save_read_set, save_write_set); } 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, 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; THD_STAGE_INFO(thd, stage_updating); transactional_table= table->file->has_transactions(); thd->abort_on_warning= !ignore && thd->is_strict_mode(); if (table->prepare_triggers_for_update_stmt_or_event()) { will_batch= FALSE; } else 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); while (!(error=info.read_record(&info)) && !thd->killed) { if (table->vfield) update_virtual_fields(thd, table, VCOL_UPDATE_FOR_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 */ store_record(table,record[1]); if (fill_record_n_invoke_before_triggers(thd, table, fields, values, 0, TRG_EVENT_UPDATE)) break; /* purecov: inspected */ found++; if (!can_compare_record || compare_record(table)) { if (table->default_field && table->update_default_fields()) { error= 1; break; } 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). */ 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]); } if (!error || error == HA_ERR_RECORD_IS_THE_SAME) { if (error != HA_ERR_RECORD_IS_THE_SAME) updated++; else error= 0; } else if (!ignore || table->file->is_fatal_error(error, HA_CHECK_ALL)) { /* 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_FATALERROR; /* Other handler errors are fatal */ prepare_record_for_error_message(error, table); table->file->print_error(error,MYF(flags)); error= 1; break; } } if (table->triggers && 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 (!thd->is_error()) table->file->unlock_row(); else { error= 1; break; } thd->get_stmt_da()->inc_current_row_for_warning(); if (thd->is_error()) { error= 1; break; } } 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->killed= KILL_QUERY; };); error= (killed_status == NOT_KILLED)? error : 1; if (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_FATALERROR)); error= 1; /* purecov: end */ } else updated-= dup_key_found; if (will_batch) table->file->end_bulk_update(); 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; THD_STAGE_INFO(thd, stage_end); (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; /* 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 ((error < 0) || thd->transaction.stmt.modified_non_trans_table) { #ifdef WITH_WSREP if (WSREP_EMULATE_BINLOG(thd) || mysql_bin_log.is_open()) #else if (mysql_bin_log.is_open()) #endif { int errcode= 0; if (error < 0) thd->clear_error(); else errcode= query_error_code(thd, killed_status == NOT_KILLED); if (thd->binlog_query(THD::ROW_QUERY_TYPE, thd->query(), thd->query_length(), transactional_table, FALSE, FALSE, errcode)) { error=1; // Rollback update } } } DBUG_ASSERT(transactional_table || !updated || thd->transaction.stmt.modified_non_trans_table); free_underlaid_joins(thd, select_lex); /* 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 (error < 0) { char buff[MYSQL_ERRMSG_SIZE]; my_snprintf(buff, sizeof(buff), ER(ER_UPDATE_INFO), (ulong) found, (ulong) updated, (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; DBUG_RETURN((error >= 0 || thd->is_error()) ? 1 : 0); err: delete select; free_underlaid_joins(thd, select_lex); table->disable_keyread(); thd->abort_on_warning= 0; DBUG_RETURN(1); exit_without_my_ok: query_plan.save_explain_data(thd->lex->explain); 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 all_fields; SELECT_LEX *select_lex= &thd->lex->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= 0; /* 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 *items) { List_iterator_fast 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 leaves, table_map tables_for_update) { List_iterator_fast 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->primary_key_is_clustered() && table1->s->primary_key != MAX_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->belong_to_view ? tl->belong_to_view->alias : tl->alias, tl2->belong_to_view ? tl2->belong_to_view->alias : tl2->alias); 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->belong_to_view ? tl->belong_to_view->alias : tl->alias, tl2->belong_to_view ? tl2->belong_to_view->alias : tl2->alias); 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; } /* 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; List *fields= &lex->select_lex.item_list; table_map tables_for_update; bool update_view= 0; /* if this multi-update was converted from usual update, here is table counter else junk will be assigned here, but then replaced with real count in open_tables() */ uint table_count= lex->table_count; const bool using_lock_tables= thd->locked_tables_mode != LTM_NONE; bool original_multiupdate= (thd->lex->sql_command == SQLCOM_UPDATE_MULTI); DBUG_ENTER("mysql_multi_update_prepare"); /* following need for prepared statements, to run next time multi-update */ thd->lex->sql_command= SQLCOM_UPDATE_MULTI; /* 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. */ if ((original_multiupdate && open_tables(thd, &table_list, &table_count, (thd->stmt_arena->is_stmt_prepare() ? MYSQL_OPEN_FORCE_SHARED_MDL : 0))) || mysql_handle_derived(lex, DT_INIT)) DBUG_RETURN(TRUE); /* 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()). */ //We need to merge for insert prior to prepare. if (mysql_handle_derived(lex, DT_MERGE_FOR_INSERT)) DBUG_RETURN(TRUE); if (mysql_handle_derived(lex, DT_PREPARE)) DBUG_RETURN(TRUE); if (setup_tables_and_check_access(thd, &lex->select_lex.context, &lex->select_lex.top_join_list, table_list, lex->select_lex.leaf_tables, FALSE, UPDATE_ACL, SELECT_ACL, FALSE)) DBUG_RETURN(TRUE); if (lex->select_lex.handle_derived(thd->lex, DT_MERGE)) DBUG_RETURN(TRUE); if (setup_fields_with_no_wrap(thd, 0, *fields, MARK_COLUMNS_WRITE, 0, 0)) DBUG_RETURN(TRUE); for (tl= table_list; tl ; tl= tl->next_local) { if (tl->view) { update_view= 1; break; } } if (update_view && check_fields(thd, *fields)) { DBUG_RETURN(TRUE); } thd->table_map_for_update= tables_for_update= get_table_map(fields); if (unsafe_key_update(lex->select_lex.leaf_tables, tables_for_update)) DBUG_RETURN(true); /* Setup timestamp handling and locking mode */ List_iterator ti(lex->select_lex.leaf_tables); 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->alias, "UPDATE"); DBUG_RETURN(TRUE); } DBUG_PRINT("info",("setting table `%s` for update", tl->alias)); /* If table will be updated we should not downgrade lock for it and leave it as is. */ } else { DBUG_PRINT("info",("setting table `%s` for read-only", tl->alias)); /* 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); tl->updating= 0; } } /* 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) { if (tl->is_jtbm()) continue; if (tl->is_merged_derived()) { TABLE_LIST *for_update= 0; if (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); } } } /* now lock and fill tables */ if (!thd->stmt_arena->is_stmt_prepare() && lock_tables(thd, table_list, table_count, 0)) { DBUG_RETURN(TRUE); } /* @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->select_lex.exclude_from_table_unique_test= TRUE; /* We only need SELECT privilege for columns in the values list */ ti.rewind(); 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: %u", tl->alias, (uint) table->grant.want_privilege)); if (tl->lock_type != TL_READ && tl->lock_type != TL_READ_NO_INSERT) { TABLE_LIST *duplicate; if ((duplicate= unique_table(thd, tl, table_list, 0))) { update_non_unique_table_error(table_list, "UPDATE", duplicate); DBUG_RETURN(TRUE); } } } /* 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->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 *fields, List *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 multi_update(table_list, &thd->lex->select_lex.leaf_tables, fields, values, handle_duplicates, ignore))) { DBUG_RETURN(TRUE); } thd->abort_on_warning= !ignore && thd->is_strict_mode(); List total_list; res= mysql_select(thd, &select_lex->ref_pointer_array, table_list, select_lex->with_wild, total_list, conds, 0, (ORDER *) NULL, (ORDER *)NULL, (Item *) NULL, (ORDER *)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) res= thd->lex->explain->send_explain(thd); } thd->abort_on_warning= 0; DBUG_RETURN(res); } multi_update::multi_update(TABLE_LIST *table_list, List *leaves_list, List *field_list, List *value_list, enum enum_duplicates handle_duplicates_arg, bool ignore_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) {} /* Connect fields with tables and create list of tables that are updated */ int multi_update::prepare(List ¬_used_values, SELECT_LEX_UNIT *lex_unit) { TABLE_LIST *table_ref; SQL_I_List update; table_map tables_to_update; Item_field *item; List_iterator_fast field_it(*fields); List_iterator_fast value_it(*values); uint i, max_fields; uint leaf_table_count= 0; List_iterator ti(*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(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, 0, *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); /* If a timestamp field settable on UPDATE is present then to avoid wrong update force the table handler to retrieve write-only fields to be able to compare records and detect data change. */ if ((table->file->ha_table_flags() & HA_PARTIAL_COLUMN_READ) && table->default_field && table->has_default_function(true)) bitmap_union(table->read_set, table->write_set); } } if (error) DBUG_RETURN(1); /* Save tables beeing 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 (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 (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); values_for_table[offset]->push_back(value); } if (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); copy_field= new Copy_field[max_fields]; DBUG_RETURN(thd->is_fatal_error != 0); } void multi_update::update_used_tables() { Item *item; List_iterator_fast it(*values); while ((item= it++)) { item->update_used_tables(); } } /* 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; 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 compler 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 ((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 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->mark_columns_needed_for_update(); table_to_update= table; // Update table on the fly continue; } } table->mark_columns_needed_for_update(); table->prepare_for_position(); /* 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 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 tbl_it(unupdated_check_opt_tables); TABLE *tbl= table; do { /* 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(); Field_string *field= new Field_string(tbl->file->ref_length, 0, tbl->alias.c_ptr(), &my_charset_bin); if (!field) DBUG_RETURN(1); field->init(tbl); /* The field will be converted to varstring when creating tmp table if table to be updated was created by mysql 4.1. Deny this. */ field->can_alter_field_type= 0; Item_field *ifield= new Item_field((Field *) field); if (!ifield) DBUG_RETURN(1); ifield->maybe_null= 0; if (temp_fields.push_back(ifield)) DBUG_RETURN(1); } while ((tbl= tbl_it++)); temp_fields.concat(fields_for_table[cnt]); /* Make an unique key over the first field to avoid duplicated updates */ bzero((char*) &group, sizeof(group)); group.asc= 1; group.item= (Item**) temp_fields.head_ref(); tmp_param->quick_group=1; tmp_param->field_count=temp_fields.elements; tmp_param->group_parts=1; tmp_param->group_length= table->file->ref_length; /* small table, ignore SQL_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, ""); thd->variables.big_tables= save_big_tables; if (!tmp_tables[cnt]) DBUG_RETURN(1); tmp_tables[cnt]->file->extra(HA_EXTRA_WRITE_CACHE); } DBUG_RETURN(0); } multi_update::~multi_update() { TABLE_LIST *table; for (table= update_tables ; table; table= table->next_local) { table->table->no_keyread= table->table->no_cache= 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 ¬_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) { 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)) { int error; if (table->default_field && table->update_default_fields()) DBUG_RETURN(1); if ((error= cur_table->view_check_option(thd, ignore)) != VIEW_CHECK_OK) { found--; if (error == VIEW_CHECK_SKIP) continue; else if (error == VIEW_CHECK_ERROR) DBUG_RETURN(1); } if (!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 ((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)) { /* 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_FATALERROR; /* Other handler errors are fatal */ prepare_record_for_error_message(error, table); table->file->print_error(error,MYF(flags)); DBUG_RETURN(1); } } else { if (error == HA_ERR_RECORD_IS_THE_SAME) { error= 0; updated--; } /* non-transactional or transactional table got modified */ /* either multi_update class' flag is raised in its branch */ if (table->file->has_transactions()) transactional_tables= TRUE; else { trans_safe= FALSE; thd->transaction.stmt.modified_non_trans_table= TRUE; } } } if (table->triggers && table->triggers->process_triggers(thd, TRG_EVENT_UPDATE, TRG_ACTION_AFTER, TRUE)) DBUG_RETURN(1); } else { int error; TABLE *tmp_table= tmp_tables[offset]; /* For updatable VIEW store rowid of the updated table and rowids of tables used in the CHECK OPTION condition. */ uint field_num= 0; List_iterator_fast
tbl_it(unupdated_check_opt_tables); TABLE *tbl= table; do { tbl->file->position(tbl->record[0]); memcpy((char*) tmp_table->field[field_num]->ptr, (char*) tbl->file->ref, tbl->file->ref_length); /* For outer joins a rowid field may have no NOT_NULL_FLAG, so we have to reset NULL bit for this field. (set_notnull() resets NULL bit only if available). */ tmp_table->field[field_num]->set_notnull(); field_num++; } while ((tbl= tbl_it++)); /* Store regular updated fields in the row. */ 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]); if (error != HA_ERR_FOUND_DUPP_KEY && error != HA_ERR_FOUND_DUPP_UNIQUE) { if (error && 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++; } } } DBUG_RETURN(0); } void multi_update::abort_result_set() { /* the error was handled or nothing deleted and no side effects return */ if (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 */ /* todo/fixme: do_update() is never called with the arg 1. should it change the signature to become argless? */ (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 */ #ifdef WITH_WSREP if (WSREP_EMULATE_BINLOG(thd) || mysql_bin_log.is_open()) #else if (mysql_bin_log.is_open()) #endif { /* 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; } 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
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); 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 ((local_error= table->file->ha_rnd_init(0))) { err_table= table; goto err; } table->file->extra(HA_EXTRA_NO_CACHE); check_opt_it.rewind(); while(TABLE *tbl= check_opt_it++) { if ((local_error= tbl->file->ha_rnd_init(1))) { err_table= tbl; goto err; } tbl->file->extra(HA_EXTRA_CACHE); } /* Setup copy functions to copy fields from temporary table */ List_iterator_fast 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 ((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 ((local_error= tmp_table->file->ha_rnd_next(tmp_table->record[0]))) { if (local_error == HA_ERR_END_OF_FILE) break; if (local_error == HA_ERR_RECORD_DELETED) continue; // May happen on dup key 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 { if ((local_error= tbl->file->ha_rnd_pos(tbl->record[0], (uchar *) tmp_table->field[field_num]->ptr))) { err_table= tbl; goto err; } field_num++; } while ((tbl= check_opt_it++)); 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(); } 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 (table->default_field && (error= table->update_default_fields())) goto err2; if (table->vfield && update_virtual_fields(thd, table, VCOL_UPDATE_FOR_WRITE)) goto err2; if ((error= cur_table->view_check_option(thd, ignore)) != VIEW_CHECK_OK) { if (error == VIEW_CHECK_SKIP) continue; else if (error == VIEW_CHECK_ERROR) { thd->fatal_error(); goto err2; } } if ((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++; else local_error= 0; } if (table->triggers && table->triggers->process_triggers(thd, TRG_EVENT_UPDATE, TRG_ACTION_AFTER, TRUE)) goto err2; } if (updated != org_updated) { if (table->file->has_transactions()) 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_FATALERROR)); } 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()) 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 (!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; if (local_error == 0 || thd->transaction.stmt.modified_non_trans_table) { #ifdef WITH_WSREP if (WSREP_EMULATE_BINLOG(thd) || mysql_bin_log.is_open()) #else if (mysql_bin_log.is_open()) #endif { int errcode= 0; if (local_error == 0) thd->clear_error(); else errcode= query_error_code(thd, killed_status == NOT_KILLED); if (thd->binlog_query(THD::ROW_QUERY_TYPE, thd->query(), thd->query_length(), transactional_tables, FALSE, FALSE, errcode)) { local_error= 1; // Rollback update } } } DBUG_ASSERT(trans_safe || !updated || thd->transaction.stmt.modified_non_trans_table); if (local_error != 0) error_handled= TRUE; // to force early leave from ::abort_result_set() if (local_error > 0) // if the above log write did not fail ... { /* Safety: If we haven't got an error before (can happen in do_updates) */ my_message(ER_UNKNOWN_ERROR, "An error occurred in multi-table update", MYF(0)); DBUG_RETURN(TRUE); } id= thd->arg_of_last_insert_id_function ? thd->first_successful_insert_id_in_prev_stmt : 0; my_snprintf(buff, sizeof(buff), ER(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); }