/* Copyright (c) 2006, 2015, Oracle and/or its affiliates. All rights reserved.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License, version 2.0,
   as published by the Free Software Foundation.

   This program is also distributed with certain software (including
   but not limited to OpenSSL) that is licensed under separate terms,
   as designated in a particular file or component or in included license
   documentation.  The authors of MySQL hereby grant you an additional
   permission to link the program and your derivative works with the
   separately licensed software that they have included with MySQL.

   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, version 2.0, 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 */

#ifndef SQL_UPDATE_INCLUDED
#define SQL_UPDATE_INCLUDED

#include "sql_class.h"       // Query_result_interceptor
#include "sql_cmd_dml.h"     // Sql_cmd_dml
#include "sql_data_change.h" // enum_duplicates

class Item;
class Query_result_update;
struct TABLE_LIST;

typedef class st_select_lex SELECT_LEX;

bool mysql_update_prepare_table(THD *thd, SELECT_LEX *select);
bool mysql_prepare_update(THD *thd, const TABLE_LIST *update_table_ref,
                          key_map *covering_keys_for_cond,
                          List<Item> &update_value_list);
bool mysql_update(THD *thd, List<Item> &fields,
                  List<Item> &values, ha_rows limit,
                  enum enum_duplicates handle_duplicates,
                  ha_rows *found_return, ha_rows *updated_return);
bool mysql_multi_update(THD *thd,
                        List<Item> *fields, List<Item> *values,
                        enum enum_duplicates handle_duplicates,
                        SELECT_LEX *select_lex,
                        Query_result_update **result);
bool records_are_comparable(const TABLE *table);
bool compare_records(const TABLE *table);

class Query_result_update :public Query_result_interceptor
{
  TABLE_LIST *all_tables; /* query/update command tables */
  TABLE_LIST *leaves;     /* list of leves of join table tree */
  TABLE_LIST *update_tables;
  TABLE **tmp_tables, *main_table, *table_to_update;
  Temp_table_param *tmp_table_param;
  ha_rows updated, found;
  List <Item> *fields, *values;
  List <Item> **fields_for_table, **values_for_table;
  uint table_count;
  /*
   List of tables referenced in the CHECK OPTION condition of
   the updated view excluding the updated table. 
  */
  List <TABLE> unupdated_check_opt_tables;
  Copy_field *copy_field;
  enum enum_duplicates handle_duplicates;
  bool do_update, trans_safe;
  /* True if the update operation has made a change in a transactional table */
  bool transactional_tables;
  /* 
     error handling (rollback and binlogging) can happen in send_eof()
     so that afterward send_error() needs to find out that.
  */
  bool error_handled;

  /**
     Array of update operations, arranged per _updated_ table. For each
     _updated_ table in the multiple table update statement, a COPY_INFO
     pointer is present at the table's position in this array.

     The array is allocated and populated during Query_result_update::prepare().
     The position that each table is assigned is also given here and is stored
     in the member TABLE::pos_in_table_list::shared. However, this is a publicly
     available field, so nothing can be trusted about its integrity.

     This member is NULL when the Query_result_update is created.

     @see Query_result_update::prepare
  */
  COPY_INFO **update_operations;

public:
  Query_result_update(TABLE_LIST *ut, TABLE_LIST *leaves_list,
                      List<Item> *fields, List<Item> *values,
                      enum_duplicates handle_duplicates);
  ~Query_result_update();
  virtual bool need_explain_interceptor() const { return true; }
  int prepare(List<Item> &list, SELECT_LEX_UNIT *u);
  bool send_data(List<Item> &items);
  bool initialize_tables (JOIN *join);
  void send_error(uint errcode,const char *err);
  int  do_updates();
  bool send_eof();
  inline ha_rows num_found()
  {
    return found;
  }
  inline ha_rows num_updated()
  {
    return updated;
  }
  virtual void abort_result_set();
};

class Sql_cmd_update : public Sql_cmd_dml
{
public:
  enum_sql_command sql_command;
  List<Item> update_value_list;

  explicit Sql_cmd_update() : sql_command(SQLCOM_UPDATE) {}

  virtual enum_sql_command sql_command_code() const { return sql_command; }

  virtual bool execute(THD *thd);
  virtual bool prepare(THD *thd) { return mysql_multi_update_prepare(thd); }
  virtual bool prepared_statement_test(THD *thd);

private:
  bool try_single_table_update(THD *thd, bool *switch_to_multitable);
  bool execute_multi_table_update(THD *thd);
  int mysql_multi_update_prepare(THD *thd);
  int mysql_test_update(THD *thd);
  bool multi_update_precheck(THD *thd, TABLE_LIST *tables);
  bool update_precheck(THD *thd, TABLE_LIST *tables);
};

#endif /* SQL_UPDATE_INCLUDED */
