如何触发删除记录

Question

我的触发看起来像这样：

CREATE TRIGGER addATicket AFTER INSERT ON ticket FOR EACH ROW BEGIN 

declare numTicket int(2) default 0; 
select count(*) into numTicket from ticket 
    where (ticket.ticket_id != new.ticket_id) 
    and (ticket.seat_code = new.seat_code); 

if (numTicket > 0) then 
    delete from ticket where ticket_id= new.ticket_id; 
end if;END 

但我的工作台捕获了一个错误：

Error Code: 1442. Can't update table 'ticket' in stored function/trigger because it is already used by statement which invoked this stored function/trigger.

我怎样才能解决这个问题。请给我一个帮助。

Answer 1

这很可能是因为您的主要INSERT查询正在触发TRIGGER在该表上持有行级锁，因此您的触发器也抱怨同样的情况。

很可能你想把AFTER INSERT ON ticket的触发定义改为BEFORE INSERT ON ticket（我的意思是用BEFORE TRIGGER代替）。

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MySql Error: Can't update table in stored function/trigger because it is already used by statement which invoked this stored function/trigger