select_stmt:
          SELECT [FIRST | ALL | DISTINCT] select_item [, select_item]...
               FROM table_ref [, table_ref]...
               [WHERE conditional_expr]
               [grouping | sorting | grouping sorting]
               [LIMIT (num {ROWS | MINS | SECS | MSECS})]
               [FOR UPDATE [OF column_name [, column_name]...]]