Function sequence_insert

sql/sql_sequence.cc:462–570

*/

bool sequence_insert(THD *thd, LEX *lex, TABLE_LIST *org_table_list)
{
  int error;
  TABLE *table;
  Reprepare_observer *save_reprepare_observer;
  sequence_definition *seq= lex->create_info.seq_create_info;
  bool temporary_table= org_table_list->table != 0;
  /*
    seq is 0 if sequence was created with CREATE TABLE instead of
    CREATE SEQUENCE
  */
  bool create_new= !seq;
  Open_tables_backup open_tables_backup;
  Query_tables_list query_tables_list_backup;
  TABLE_LIST table_list;                        // For sequence table
  DBUG_ENTER("sequence_insert");
  DBUG_EXECUTE_IF("kill_query_on_sequence_insert",
                  thd->set_killed(KILL_QUERY););

  if (create_new && !(seq= new (thd->mem_root) sequence_definition))
    DBUG_RETURN(TRUE);

  /* If not temporary table */
  if (!temporary_table)
  {
    /*
      The following code works like open_system_tables_for_read()
      The idea is:
      - Copy the table_list object for the sequence that was created
      - Backup the current state of open tables and create a new
        environment for open tables without any tables opened
     - open the newly sequence table for write
     This is safe as the sequence table has a mdl lock thanks to the
     create sequence statement that is calling this function
    */

    table_list.init_one_table(&org_table_list->db,
                              &org_table_list->table_name, 
                              NULL, TL_WRITE_DEFAULT);
    table_list.updating=  1;
    table_list.open_strategy= TABLE_LIST::OPEN_IF_EXISTS;
    table_list.open_type= OT_BASE_ONLY;

    DBUG_ASSERT(!thd->locked_tables_mode ||
                (thd->variables.option_bits & OPTION_TABLE_LOCK));
    lex->reset_n_backup_query_tables_list(&query_tables_list_backup);
    thd->reset_n_backup_open_tables_state(&open_tables_backup);

    /*
      The FOR CREATE flag is needed to ensure that ha_open() doesn't try to
      read the not yet existing row in the sequence table
    */
    thd->open_options|= HA_OPEN_FOR_CREATE;
    /*
      We have to reset the reprepare observer to be able to open the
      table under prepared statements.
    */
    save_reprepare_observer= thd->m_reprepare_observer;