T-SQL 集锦
2012-03-16 16:04 河蟹社会 阅读(169) 评论(0) 编辑 收藏 举报alter table SubscribeList add id int identity(1,1)
select max(id) as id into #t from SubscribeList group by mail
delete from SubscribeList where id not in (select id from #t)
drop table #t
alter table SubscribeList drop column id
删除表中重复字段,保留一个.