PHP从MySQL中删除两个表不匹配的行

Question

我有两张桌子：

tickets
tickets_updates

我认为tickets_updates中有一些额外的行，tickets表中不存在记录

运行SQL代码的最佳方式是：

从tickets_updates ticket_seq不在tickets（序列）中删除所有内容

票证表中的

序列与tickets_updates表中的ticket_seq匹配

Answer 1

DELETE FROM tickets_updates
WHERE  ticket_seq NOT IN (SELECT sequence
                           FROM   tickets)  

Answer 2

DELETE FROM tickets_updates tu
LEFT JOIN tickets t ON tu.ticket_seq = t.sequence
WHERE t.sequence IS NULL

Answer 3

试试这个：

DELETE FROM ticket_updates
WHERE NOT EXISTS
    (SELECT 'x' from tickets
    WHERE tickets.sequence = ticket_updates.ticket_seq)