数据库重复问题

判断日期是否有效
update Sheet1$ set date=null
where
Isdate(date)=0


select * from sheet1 where 社区网格 is null or 楼栋名称 is null or 单元 is null or 房间号 is null




身份证号码
select * from sheet1
where isdate(substring([身份证号],7,4)+'-'+substring([身份证号],11,2)+'-'+substring([身份证号],13,2))<>1





是否有重复
select * from 
(
SELECT *
  FROM sheet1

WHERE [身份证号] in

(
select [身份证号] from sheet1 group by [身份证号] having count(*)>1
)
) as tb order by tb.[身份证号]