这个SQL语句有什么问题?

[kingtiy]

select acc_nbr,sum(c1), sum(c2), sum(c3) from
(
select acc_nbr,charge c1,0 c2,0 c3
from A
union all
select acc_nbr,0 c1,charge c2,0 c3
from B
union all
select acc_nbr,0 c1,0 c2 ,charge c3
from C
)
group by acc_nbr
A,B,C三个表结构相同,字段如下:
acc_nbr char(10) charge int (10)

[zjcxc]

select acc_nbr,sum(c1), sum(c2), sum(c3) from
(
select acc_nbr,charge c1,0 c2,0 c3
from A
union all
select acc_nbr,0 c1,charge c2,0 c3
from B
union all
select acc_nbr,0 c1,0 c2 ,charge c3
from C
)a -- 少一别名
group by acc_nbr

[fcuandy]

没什么大问题。
只是 union联合查询组合成的子查询需要一个别名。

select acc_nbr,sum(c1), sum(c2), sum(c3) from
(
select acc_nbr,charge c1,0 c2,0 c3
from A
union all
select acc_nbr,0 c1,charge c2,0 c3
from B
union all
select acc_nbr,0 c1,0 c2 ,charge c3
from C
) x
group by acc_nbr

[LouisXIV]

select acc_nbr,sum(c1), sum(c2), sum(c3) from
(
select acc_nbr,charge c1,0 c2,0 c3
from A
union all
select acc_nbr,0 c1,charge c2,0 c3
from B
union all
select acc_nbr,0 c1,0 c2 ,charge c3
from C
)a--这里，表别名
group by acc_nbr

[kingtiy]

谢谢大家~~~~

[sharelove]

哇！CSDN居然还有钻石？第一次看到！回个贴！

[蓝黑色时代]

偶也是第一次看到！