数据库--查询--按小时查询&在where里面使用sum函数

Posted 2020-10-17 EasonDongH

查询：将数据库-表中-若干日期-按一天24小时，将所有日期同一时间的数据求和。

学习点：将数据按小时分组求和

1 declare @BgainTime varchar(50)=‘2017-11-01‘  
2 declare @EndTime varchar(50)  =‘2017-12-01‘
3 --每小时发药处方量
4 select ‘时间‘=datepart(hh,ReceiveTime),‘发药量‘=count(*) from Prescription 
5 where ReceiveTime between  @BgainTime and @EndTime
6 group by datepart(hh,ReceiveTime)
7 order by datepart(hh,ReceiveTime)

如果想在where条件使用sum函数，通过having来实现：

select  PrescCode from PrescriptionDetail group by PrescCode having sum(OutQuantity)>=sum(Quantity)