From Chaehyun

join

• INSERT IGNORE INTO user_log (user_id, item_id, date_created, tag) SELECT a.id, b.code, b.date, 'like' FROM user_id a, review b WHERE a.author=b.author AND b.point >= 7;

update

• UPDATE TBL_MENU AS a SET CNT = (SELECT COUNT(*) FROM TBL_ORDER_DETAIL WHERE MN_IDX = a.MN_IDX);

on duplicate key update

• insert into ITEM_RECO2 (reco_id, service_id, last_updated) values('00000ded874a175e', 4, '2013-03-20 02:12:12'), ('0000000000', 4, '2013-03-20 02:12:12'), ('0000106d0c44711d', 4, '2013-03-20 02:12:12') ON DUPLICATE KEY UPDATE last_updated='2016-03-20 02:12:12';