SQL查找某列中數據相同的數據

select 列名 from 表名 where 列名 in (select 列名 from 表名 group by 列名 having count(列名) > 1)

 

假設表名bai是num，列名是a，則查詢語句du為：

SELECT * FROM num WHERE a IN(

SELECT a FROM num GROUP BY a HAVING COUNT(a)>1

)