delete t1,t2,t3,t4 from t1 left join t2 on t1.id=t2.id left join t3 on t1.id=t3.id left join t4  on t1.id=t4.id where t1.id=12

你的问题直接四条sql执行就行了
你并不能保证每个表都有你要删的记录 怎么join都可能有问题

START TRANSACTION;
    DELETE FROM t1 WHERE id=12;
    DELETE FROM t2 WHERE id=12;
    DELETE FROM t3 WHERE id=12;
    DELETE FROM t4 WHERE id=12;
COMMIT;

# ROLLBACK;  # 如果commit有错，请回滚．