不同表中的字段相加?

[QiQi_yun]

select a.BlockID as '卡号',
sum(a.SavingTotal)as '期初累计充值',
sum(c.PayMoney) as '本次充值',
sum (a.SavingTotal+c.PayMoney) as '充值合计',
sum(case when datediff(day,b.ConsumeDate,getdate())=0 then 
sum(a.AlreadlyConsume)as '累计消费金额',
sum(a.[Money]) as '卡内余额' 
from tb_ConsumeCar as a 
,tb_ClientConsume as b
,tb_MemberConsumptionList as c
where a.BlockID=b.BlockID
and b.LinkCode = c.LinkCode
and c.ConsumeType=2
group by a.BlockID

注意

sum (a.SavingTotal+c.PayMoney) as '充值合计',

这样可以吧?如果可以,相减也是一个道理可行吧?

[wgzaaa]

可以

[ygf6754]

不错

[wgzaaa]

可行

[wgzaaa]

注意空值的影响
不如改为 sum(a.SavingTotal)+sum(c.PayMoney)

[QiQi_yun]

哦,我还担心不行呢!谢谢!!

[hyqwan11112]

没问题，这两个字段如果有可空的，加个isnull

[昵称被占用了]

sum (a.SavingTotal+c.PayMoney) as '充值合计',

在某些情况下容易有错，而且不容易发现，就是在a.SavingTotal和c.PayMoney一个或者两个可空得情况下或者外连接的情况下，最好写成
sum (a.SavingTotal)+sum(c.PayMoney) as '充值合计',
自动把null解释成0

[hyde100]

因为是连接过来的，所以可以的，最好有ISNULL判断，要不然会warning

[tcxx2008]

关注了关注了

[zhangyh_136]

select a.BlockID as '卡号',
sum(a.SavingTotal)as '期初累计充值',
sum(c.PayMoney) as '本次充值',
sum (a.SavingTotal+c.PayMoney) as '充值合计',
sum(case when datediff(day,b.ConsumeDate,getdate())=0 then
sum(a.AlreadlyConsume)as '累计消费金额',
sum(a.[Money]) as '卡内余额'
from tb_ConsumeCar as a
,tb_ClientConsume as b
,tb_MemberConsumptionList as c
where a.BlockID=b.BlockID
and b.LinkCode = c.LinkCode
and c.ConsumeType=2
group by a.BlockID

不判断空值???

[jiamingwudi]

又学了一手，帮顶