Function find_dup_table

sql/sql_base.cc:1151–1282

*/

static
TABLE_LIST* find_dup_table(THD *thd, TABLE_LIST *table, TABLE_LIST *table_list,
                           uint check_flag)
{
  TABLE_LIST *res= 0;
  DBUG_ENTER("find_dup_table");
  DBUG_PRINT("enter", ("table alias: %s", table->alias.str));

  /*
    If this function called for query which update table (INSERT/UPDATE/...)
    then we have in table->table pointer to TABLE object which we are
    updating even if it is VIEW so we need TABLE_LIST of this TABLE object
    to get right names (even if lower_case_table_names used).

    If this function called for CREATE command that we have not opened table
    (table->table equal to 0) and right names is in current TABLE_LIST
    object.
  */
  if (table->table &&
      thd->lex->sql_command != SQLCOM_UPDATE &&
      thd->lex->sql_command != SQLCOM_UPDATE_MULTI &&
      thd->lex->sql_command != SQLCOM_DELETE &&
      thd->lex->sql_command != SQLCOM_DELETE_MULTI)
  {
    /* All MyISAMMRG children are plain MyISAM tables. */
    DBUG_ASSERT(table->table->file->ht->db_type != DB_TYPE_MRG_MYISAM);

    table= table->find_underlying_table(table->table);
    /*
      as far as we have table->table we have to find real TABLE_LIST of
      it in underlying tables
    */
    DBUG_ASSERT(table);
  }
  const Lex_ident_db d_name= table->db;
  const Lex_ident_table t_name= table->table_name;
  const Lex_ident_table t_alias= table->alias;

  DBUG_PRINT("info", ("real table: %s.%s", d_name.str, t_name.str));
  for (TABLE_LIST *tl= table_list; tl ; tl= tl->next_global, res= 0)
  {
    if (tl->select_lex && tl->select_lex->master_unit() &&
        tl->select_lex->master_unit()->executed)
    {
      /*
        There is no sense to check tables of already executed parts
        of the query
      */
      continue;
    }
    /*
      Table is unique if it is present only once in the global list
      of tables and once in the list of table locks.
    */
    if (! (res= find_table_in_global_list(tl, &d_name, &t_name)))
      break;
    tl= res;                       // We can continue search after this table