text: DROP TABLE IF EXISTS common;
  DROP TABLE IF EXISTS null1;
  DROP TABLE IF EXISTS null2;
  
  CREATE TABLE common
  (
      id      BIGINT(20) NOT NULL,
      name    VARCHAR(20) NOT NULL,
      deleted INT(11) NOT NULL DEFAULT 0,
      PRIMARY KEY (id)
  );
  
  CREATE TABLE null1
  (
      id      BIGINT(20) NOT NULL,
      name    VARCHAR(20) NOT NULL,
      deleted INT(11),
      PRIMARY KEY (id)
  );
  
  CREATE TABLE null2
  (
      id       BIGINT(20) NOT NULL,
      name     VARCHAR(20) NOT NULL,
      del_time TIMESTAMP,
      PRIMARY KEY (id)
  );