delete dgpage where id in ( select a.id from dgpage a, dgpage b where a.mail = b.mail and a.id > b.id )
删除表:dgpage中Mail重复的记录并保留最近一条.
delete dgpage where id in ( select a.id from dgpage a, dgpage b where a.mail = b.mail and a.id <b.id )
以上就是【删除重复的记录,并保存第一条记录或保存最后一条记录】的全部内容了,欢迎留言评论进行交流!