1 /* Copyright (c) 2006, 2020, Oracle and/or its affiliates. All rights reserved. 2 3 This program is free software; you can redistribute it and/or modify 4 it under the terms of the GNU General Public License, version 2.0, 5 as published by the Free Software Foundation. 6 7 This program is also distributed with certain software (including 8 but not limited to OpenSSL) that is licensed under separate terms, 9 as designated in a particular file or component or in included license 10 documentation. The authors of MySQL hereby grant you an additional 11 permission to link the program and your derivative works with the 12 separately licensed software that they have included with MySQL. 13 14 This program is distributed in the hope that it will be useful, 15 but WITHOUT ANY WARRANTY; without even the implied warranty of 16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 GNU General Public License, version 2.0, for more details. 18 19 You should have received a copy of the GNU General Public License 20 along with this program; if not, write to the Free Software 21 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ 22 23 #ifndef SQL_DELETE_INCLUDED 24 #define SQL_DELETE_INCLUDED 25 26 #include <stddef.h> 27 #include <sys/types.h> 28 29 #include "my_base.h" // ha_rows 30 #include "my_sqlcommand.h" 31 #include "my_table_map.h" 32 #include "sql/query_result.h" // Query_result_interceptor 33 #include "sql/sql_cmd_dml.h" // Sql_cmd_dml 34 35 class Item; 36 class SELECT_LEX_UNIT; 37 class Select_lex_visitor; 38 class THD; 39 class Unique; 40 struct TABLE; 41 struct TABLE_LIST; 42 template <class T> 43 class List; 44 template <typename T> 45 class SQL_I_List; 46 47 class Query_result_delete final : public Query_result_interceptor { 48 /// Pointers to temporary files used for delayed deletion of rows 49 Unique **tempfiles; 50 /// Pointers to table objects matching tempfiles 51 TABLE **tables; 52 /// Number of tables being deleted from 53 uint delete_table_count; 54 /// Number of rows produced by the join 55 ha_rows found_rows; 56 /// Number of rows deleted 57 ha_rows deleted_rows; 58 /// Handler error status for the operation. 59 int error; 60 /// Map of all tables to delete rows from 61 table_map delete_table_map; 62 /// Map of tables to delete from immediately 63 table_map delete_immediate; 64 // Map of transactional tables to be deleted from 65 table_map transactional_table_map; 66 /// Map of non-transactional tables to be deleted from 67 table_map non_transactional_table_map; 68 /// True if the full delete operation is complete 69 bool delete_completed; 70 /// True if some actual delete operation against non-transactional table done 71 bool non_transactional_deleted; 72 /* 73 error handling (rollback and binlogging) can happen in send_eof() 74 so that afterward send_error() needs to find out that. 75 */ 76 bool error_handled; 77 78 public: Query_result_delete()79 Query_result_delete() 80 : Query_result_interceptor(), 81 tempfiles(nullptr), 82 tables(nullptr), 83 delete_table_count(0), 84 found_rows(0), 85 deleted_rows(0), 86 error(0), 87 delete_table_map(0), 88 delete_immediate(0), 89 transactional_table_map(0), 90 non_transactional_table_map(0), 91 delete_completed(false), 92 non_transactional_deleted(false), 93 error_handled(false) {} need_explain_interceptor()94 bool need_explain_interceptor() const override { return true; } 95 bool prepare(THD *thd, List<Item> &list, SELECT_LEX_UNIT *u) override; 96 bool send_data(THD *thd, List<Item> &items) override; 97 void send_error(THD *thd, uint errcode, const char *err) override; 98 bool optimize() override; start_execution(THD *)99 bool start_execution(THD *) override { 100 delete_completed = false; 101 return false; 102 } 103 int do_deletes(THD *thd); 104 int do_table_deletes(THD *thd, TABLE *table); 105 bool send_eof(THD *thd) override; num_deleted()106 inline ha_rows num_deleted() { return deleted_rows; } 107 void abort_result_set(THD *thd) override; 108 void cleanup(THD *thd) override; 109 bool immediate_update(TABLE_LIST *t) const override; 110 }; 111 112 class Sql_cmd_delete final : public Sql_cmd_dml { 113 public: Sql_cmd_delete(bool multitable_arg,SQL_I_List<TABLE_LIST> * delete_tables_arg)114 Sql_cmd_delete(bool multitable_arg, SQL_I_List<TABLE_LIST> *delete_tables_arg) 115 : multitable(multitable_arg), delete_tables(delete_tables_arg) {} 116 sql_command_code()117 enum_sql_command sql_command_code() const override { 118 return multitable ? SQLCOM_DELETE_MULTI : SQLCOM_DELETE; 119 } 120 is_single_table_plan()121 bool is_single_table_plan() const override { return !multitable; } 122 123 virtual bool accept(THD *thd, Select_lex_visitor *visitor) override; 124 125 protected: 126 bool precheck(THD *thd) override; 127 128 bool prepare_inner(THD *thd) override; 129 130 bool execute_inner(THD *thd) override; 131 132 private: 133 bool delete_from_single_table(THD *thd); 134 135 bool multitable; 136 /** 137 References to tables that are deleted from in a multitable delete statement. 138 Only used to track such tables from the parser. In preparation and 139 optimization, use the TABLE_LIST::updating property instead. 140 */ 141 SQL_I_List<TABLE_LIST> *delete_tables; 142 }; 143 144 #endif /* SQL_DELETE_INCLUDED */ 145