68 sql 查找表中同一个字段出现的重复项次数 视图

1.查找表中同一个字段出现的重复项次数

SELECT `contractid`,count(`contractid`) FROM `dcv2_data_preferentiadetails`  GROUP BY `contractid`
ORDER BY  count(`contractid`)  desc

2.或者

SELECT `organcode` , COUNT( * )

FROM `dcv2_data_leasecontract`

GROUP BY organcode

HAVING COUNT( id ) >1

LIMIT 0 , 30

3.建立视图

select `epid`,count(distinct batchno),sum(money5),`year` from `dcv2_data_applymaindetails`
where `year` is not null