我的表base 字段：name，cardid，workunit，sex， addr，zip；有3万条记录，我想找到name，cardid一样的记录并删除，该怎样写？

delete a from base a
inner join
(
select name,cardid
from base
group by name,cardid
having count(name)>1
)b
on a.name=b.name and a.cardid=b.cardid

delete from base
where base.name=base.cardid
好象就可以的啊。我试了一下。可以的

你的问题好像说的不是太清楚呀。