在另一个表中添加行存在标志,并使用 group by

Add flag for row existence in another table with group by

提问人:Alvaro 提问时间:9/15/2020 最后编辑:Alvaro 更新时间:9/15/2020 访问量:403

问:

对于下面的查询,我想有一个标志,其计算结果为 0 如果表中不存在 from 视图和 否则为 1isHoldbillNoviewBillsonHold

select max(t.id) TrackingID , max(vb.billNo) billNo, cb.id  ,
max(case when vb.[count] > 1 then 1 else 0 end) isMultiple ,
max(case when t.TrackingID = 31 then 1 else 0 end) IsCancelled,
max(case when exists (select 1 from OnHold oh
where oh.billNo = billNo) then 1 else 0 end) IsHold

from viewBills vb
join tracking t on vb.billNo = t.billNo
join customerBills cb on vb.billNo = cb.billNo 
join customerPieces cp on  cb.id = cp.customerBillId
where cb.statusid <> 3
group by cb.id

我在执行时收到此错误

Cannot perform an aggregate function on an expression 
containing an aggregate or a subquery.

这是合理的,但如何实现呢?

sql sql server 布尔逻辑

评论

0赞 Gordon Linoff 9/15/2020
您在 中,但在 中。cb.idselectcp.idgroup by
0赞 Alvaro 9/15/2020
实际上这是一个错别字
1赞 shawnt00 9/15/2020
您可以将其移动到outer apply

答:

1赞 Gordon Linoff 9/15/2020 #1

您可以使用 or a 将逻辑移动到子句中:outer applyleft joinFROM

select max(t.id) as TrackingID , max(vb.billNo) as billNo, cb.id ,
       max(case when vb.[count] > 1 then 1 else 0 end) as isMultiple,
       max(case when t.TrackingID = 31 then 1 else 0 end) as IsCancelled,
       max(case when oh.billNo is not null then 1 else 0 end) as IsHold
from viewBills vb join
     tracking t
     on vb.billNo = t.billNo join
     customerBills cb
     on vb.billNo = cb.billNo  join
     customerPieces cp
     on cb.id = cp.customerBillId outer apply
     (select top (1) oh.*
      from OnHold oh
      where oh.billNo = cb.billNo
     ) oh
where cw.statusid <> 3
group by cb.id;

评论

0赞 Alvaro 9/15/2020
如何使用左连接来做到这一点?
0赞 Gordon Linoff 9/15/2020
@Alvaro . . .我更喜欢,这就是我使用这种方法的原因。outer applyleft join
0赞 Alvaro 9/15/2020
我可以知道为什么吗?效率更高吗?
0赞 Gordon Linoff 9/15/2020
@Alvaro . . .它只选择一行,因此如果有多个可能的匹配项,聚合不必做太多的工作。
1赞 Venkataraman R 9/15/2020 #2

您可以转到 LEFT OUTER JOIN 并按如下方式进行聚合:

select max(t.id) TrackingID , max(vb.billNo) billNo, cb.id  ,
max(case when vb.[count] > 1 then 1 else 0 end) isMultiple ,
max(case when t.TrackingID = 31 then 1 else 0 end) IsCancelled,
max(case when oh.billNo IS NOT NULL then 1 else 0 end) IsHold

from viewBills vb
join tracking t on vb.billNo = t.billNo
join customerBills cb on vb.billNo = cb.billNo 
join customerPieces cp on  cb.id = cp.customerBillId
LEFT OUTER JOIN OnHold oh ON oh.billNo = vb.billNo
where cb.statusid <> 3
group by cb.id