84 lines
3.2 KiB
C++
84 lines
3.2 KiB
C++
/* Copyright (c) 2006, 2024, Oracle and/or its affiliates.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License, version 2.0,
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as published by the Free Software Foundation.
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This program is designed to work with certain software (including
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but not limited to OpenSSL) that is licensed under separate terms,
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as designated in a particular file or component or in included license
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documentation. The authors of MySQL hereby grant you an additional
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permission to link the program and your derivative works with the
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separately licensed software that they have either included with
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the program or referenced in the documentation.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License, version 2.0, for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
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#ifndef SQL_DELETE_INCLUDED
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#define SQL_DELETE_INCLUDED
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#include "my_sqlcommand.h"
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#include "my_table_map.h"
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#include "sql/sql_cmd_dml.h" // Sql_cmd_dml
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class JOIN;
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class Select_lex_visitor;
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class THD;
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class Table_ref;
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template <typename T>
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class SQL_I_List;
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class Sql_cmd_delete final : public Sql_cmd_dml {
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public:
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Sql_cmd_delete(bool multitable_arg, SQL_I_List<Table_ref> *delete_tables_arg)
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: multitable(multitable_arg), delete_tables(delete_tables_arg) {}
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enum_sql_command sql_command_code() const override {
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return multitable ? SQLCOM_DELETE_MULTI : SQLCOM_DELETE;
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}
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bool is_single_table_plan() const override { return !multitable; }
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bool accept(THD *thd, Select_lex_visitor *visitor) override;
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protected:
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bool precheck(THD *thd) override;
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bool check_privileges(THD *thd) override;
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bool prepare_inner(THD *thd) override;
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bool execute_inner(THD *thd) override;
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private:
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bool delete_from_single_table(THD *thd);
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bool multitable;
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/**
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References to tables that are deleted from in a multitable delete statement.
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Only used to track such tables from the parser. In preparation and
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optimization, use the Table_ref::updating property instead.
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*/
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SQL_I_List<Table_ref> *delete_tables;
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};
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/// Find out which of the delete target tables can be deleted from immediately
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/// while scanning. This is used by the old optimizer *after* the plan has been
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/// created. The hypergraph optimizer does not use this function, as it makes
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/// the decision about immediate delete *during* planning, not after planning.
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table_map GetImmediateDeleteTables(const JOIN *join, table_map delete_tables);
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/// Checks if the sql_safe_updates option is enabled, and raises an error and
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/// returns true if the statement is likely to delete or update a large number
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/// of rows. Specifically, it raises an error if there is a full table scan or
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/// full index scan of one of the tables deleted from, and there is no LIMIT
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/// clause.
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bool CheckSqlSafeUpdate(THD *thd, const JOIN *join);
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#endif /* SQL_DELETE_INCLUDED */
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