摘要：
a.删除完全重复数据create table #t1(SN varchar(30))insert into #t1 values('a'),('a'),('a'),('b'),('b'),('c')select * from (select *,ROW_NUMBER()over(partition by sn order by sn) as seq from #t1) as aadelete aa from (select *,ROW_NUMBER()over(partition by sn ord 阅读全文