mysql刪除表中某一欄位重複的記錄

比如，表：event（id int（10） auto_increment primary key，
sid int（10）not null，
detail text）

我想刪除表event中sid重複的記錄，請問有沒有這樣SQL語句？或是通過其它方法？

複製代碼 代碼如下:delete from event as e
where id != (select min(id) from event where sid=e.sid);

or 複製代碼 代碼如下:delete from event
where sid not in (select mid from (select sid ,min(id) as mid from event group by sid))

應該是有用的代碼複製代碼 代碼如下:alter ignore table event add unique index idu_sid (sid);
alter table event drop index idu_sid;