一般大家也许会碰到这个问题,大家可以参考下,讲的比较详细
比如,表:event(id int(10) auto_increment primary key,
sid int(10)not null,
detail text)
我想删除表event中sid重复的记录,请问有没有这样SQL语句?或是通过其它方法?
代码如下:
delete from event as e
where id != (select min(id) from event where sid=e.sid);
or
代码如下:
delete from event
where sid not in (select mid from (select sid ,min(id) as mid from event group by sid))
应该是有用的代码
代码如下:
alter ignore table event add unique index idu_sid (sid);
alter table event drop index idu_sid;