forked from StoneAtom/StoneDB
89 lines
2.6 KiB
C++
89 lines
2.6 KiB
C++
#ifndef SQL_TRUNCATE_INCLUDED
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#define SQL_TRUNCATE_INCLUDED
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/* Copyright (c) 2010, 2021, 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 also distributed 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 included with MySQL.
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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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#include "my_global.h"
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#include "sql_cmd_dml.h" // Sql_cmd_dml
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class MDL_ticket;
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class THD;
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struct TABLE_LIST;
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/**
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Sql_cmd_truncate_table represents the TRUNCATE statement.
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*/
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class Sql_cmd_truncate_table : public Sql_cmd_dml
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{
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private:
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/* Set if a lock must be downgraded after truncate is done. */
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MDL_ticket *m_ticket_downgrade;
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public:
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/**
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Constructor, used to represent a TRUNCATE statement.
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*/
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Sql_cmd_truncate_table()
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{}
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virtual ~Sql_cmd_truncate_table()
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{}
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/**
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Execute a TRUNCATE statement at runtime.
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@param thd the current thread.
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@return false on success.
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*/
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bool execute(THD *thd);
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virtual enum_sql_command sql_command_code() const
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{
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return SQLCOM_TRUNCATE;
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}
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virtual bool prepared_statement_test(THD *) { return false; }
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virtual bool prepare(THD *) { return false; }
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virtual void cleanup(THD *) {}
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protected:
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enum truncate_result{
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TRUNCATE_OK=0,
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TRUNCATE_FAILED_BUT_BINLOG,
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TRUNCATE_FAILED_SKIP_BINLOG
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};
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/** Handle locking a base table for truncate. */
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bool lock_table(THD *, TABLE_LIST *, bool *);
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/** Truncate table via the handler method. */
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enum truncate_result handler_truncate(THD *, TABLE_LIST *, bool);
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/**
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Optimized delete of all rows by doing a full regenerate of the table.
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Depending on the storage engine, it can be accomplished through a
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drop and recreate or via the handler truncate method.
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*/
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bool truncate_table(THD *, TABLE_LIST *);
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};
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#endif
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