select *,identity(int,1,1) as sid into # from tb delete # where sid<=300 alter table # drop column sid truncate table tb insert into tb select * from #
select top 300 * from tablename
delete from tablename where id(列名) in (select top 300 id from tablename)
delete # where sid<=300
alter table # drop column sid
truncate table tb
insert into tb
select * from #