初学者求教关于选取重复数据sql
菜鸟求教关于选取重复数据sql
现在有一张detail表,数据如下
要求是选出每个月都来电的号码并计算每个月该号码的来电次数
------解决方案--------------------
------解决方案--------------------
先查找每个月都来电话的电话号码,再统计每个号码每个月打的次数
现在有一张detail表,数据如下
要求是选出每个月都来电的号码并计算每个月该号码的来电次数
------解决方案--------------------
select callin_num,count(distinct month) from t group by callinnum
having count(distinct month)=(select count(distinct month) from t);
------解决方案--------------------
先查找每个月都来电话的电话号码,再统计每个号码每个月打的次数
select count(month),month,callin_num from detail
where callin_num in(
select A.CALLIN_NUM CALL_COUNT from
(SELECT DISTINCT * FROM DETAIL) A
GROUP BY
A.CALLIN_NUM
HAVING
COUNT(A.CALLIN_NUM)=(SELECT COUNT(DISTINCT MONTH) FROM DETAIL))
group by month,callin_num