mysql查询某一字段重复
mysql查询某一字段重复
如下表,如何知道下表有没有手机号相同的,并且找到他?
第一步:找到重复的手机号;
SELECT phone FROM all_supplier GROUP BY phone
HAVING COUNT(phone
)>1;
第二步:找到手机号为重复的记录
SELECT * FROM all_supplier WHERE phone IN
(SELECT phone FROM all_supplier GROUP BY phone
HAVING COUNT(phone
)>1);