Mysql删除重复数据

今天需要删除一个表中的重复数据，先查询出重复的数据,sql:

select * from tpf.order_unused where airTicket in(select airTicket from order_unused GROUP BY airTicket having count(id)>1)
and id not in(SELECT min(id) from order_unused GROUP BY airTicket having count(id)>1);

然后本来向直接将select * 换成delete 就可以了，但是执行后出现错误，上网查了一下，发现是因为mysql不支持

不能先select出同一表中的某些值，再update这个表(在同一语句中) 

所以需要使用临时表，sql 如下：

create table tmp_order_unused as select id from tpf.order_unused where airTicket in(select airTicket from order_unused GROUP BY airTicket having count(id)>1)
and id not in(SELECT min(id) from order_unused GROUP BY airTicket having count(id)>1);

先将重复的数据id放到一个临时表中，再通过临时表把本表中的对应id的数据删除即可：

delete from tpf.order_unused where id in(select id from tmp_order_unused)