查询KQLeaveRecord在某时间段里的某个ClassID的记录条数
(select COUNT(*) from KQLeaveRecord where classid=1100
and ((BigenDate between '2017-09-07 0:0:0' and '2017-09-07 23:59:0' and
EndDate between '2017-09-07 0:0:0' and '2017-09-07 23:59:0' )
or (BigenDate<='2017-09-07 0:0:0' and EndDate >='2017-09-07 23:59:0')))
连接查出数据
SELECT a.CABID, a.ClassID,(select Count(*) from XSClassStudent where ClassID=a.ClassID and StuState=1) ClassNumber,
(select COUNT(*) from KQLeaveRecord where classid=a.ClassID
and (BigenDate between '2017-09-07 0:0:0' and '2017-09-07 23:59:0' and
EndDate between '2017-09-07 0:0:0' and '2017-09-07 23:59:0' )
or (BigenDate<='2017-09-07 0:0:0' and EndDate >='2017-09-07 23:59:0')) qq,
a.State AS ClassState,
b.KQClassID, b.KQDate, b.KQClassNumber,b.KQAttendanceNumber, b.KQAttendanceLv, b.State AS KQState,
c.NUMCLASSID FROM
KQClassAttendanceBase a LEFT OUTER JOIN KQClassRecord b ON
a.ClassID = b.ClassID and b.KQDate='2017-09-07'
LEFT OUTER JOIN XSClassInfo c ON
a.ClassID = c.ClassID
where a.State=1
子查询QQ一列为重复数据，猜测是ClassID未对应，不知道具体原因，球解决办法
个人建议用select新表来改写and后面的语句。顺便请问一下，你写and后面的语句的逻辑是什么，你自己会不会觉得不太符合语法？
后面的，假如时间段条件是今天0点到23点59，一种情况是开始时间和结束时间都在今天的时间里面，or 后面的情况是开始时间在昨天或者前几天，结束时间在明天或者后几天，只要有便会记录条数，