求一SqlServer语句
[A表]

idBBB
510
615

[B表]

idBBB
65

我要的结果是当[A表] id = [B表] id 的时候 [A表] BBB + [B表] BBB

如果[B表] id 没有包含[A表] id的时候只取[A表] BBB字段的值

要的结果如下:

10
20
[解决办法]
select id,sum(bbb)
from (
select id,bbb
from a
union all
select id,bbb
from b)
a
group by id
[解决办法]
try this,

select a.id,
       a.BBB+isnull(b.BBB,0) 'BBB'
 from [A表] a
 left join [B表] b on a.id=b.id