text: ---- drop ----
  DROP TABLE IF EXISTS `test_table`;
  
  ---- create ----
  create table
  IF not exists `test_table`
  (
   `memo_id`               INT
  (20) AUTO_INCREMENT,
   `memo`             VARCHAR
  (20) NOT NULL,
   `memo_author`             VARCHAR
  (20) NOT NULL,
    PRIMARY KEY
  (`memo_id`)
  );