text: INSERT INTO sample_db.user (nick_name, sex, prefecture_id, email, memo) VALUES ('test user 1', 'M', 1, 'test.user1@example.com', 'memo 1');
  INSERT INTO sample_db.user (nick_name, sex, prefecture_id, email, memo) VALUES ('test USER 2', 'F', 2, 'test.user2@example.com', 'MEMO 2');
  INSERT INTO sample_db.user (nick_name, sex, prefecture_id, email, memo) VALUES ('test ユーザー 3', 'M', 3, 'test.user3@example.com', 'メモ3');
  INSERT INTO sample_db.user (nick_name, sex, prefecture_id, email, memo) VALUES ('TEST user 4', 'F', 4, 'test.user4@example.com', 'memo 4');
  INSERT INTO sample_db.user (nick_name, sex, prefecture_id, email, memo) VALUES ('test_user_5', 'M', 5, 'test.user5@example.com', null);
  INSERT INTO sample_db.user (nick_name, sex, prefecture_id, email, memo) VALUES ('user 6 test', 'F', 6, 'test.user6@example.com', null);
  INSERT INTO sample_db.user (nick_name, sex, prefecture_id, email, memo) VALUES ('user_7_test', 'M', 0, 'test.user7@example.com', null);
  