有两个表 t_A 与 t_B
表t_A如下:
----------------------------------
Ca Da
----------------------------------
A 1
B 2
C 3表t_B如下:
----------------------------------
Cb Db
----------------------------------
B 2
C 3
D 4要生成如下数据,用一条语句怎么写
----------------------------------
Cc Dc
----------------------------------
A 1
B 4
C 6
D 4怎么写?
表t_A如下:
----------------------------------
Ca Da
----------------------------------
A 1
B 2
C 3表t_B如下:
----------------------------------
Cb Db
----------------------------------
B 2
C 3
D 4要生成如下数据,用一条语句怎么写
----------------------------------
Cc Dc
----------------------------------
A 1
B 4
C 6
D 4怎么写?
(select ca,cb from tb_a
union all
select * from tb_b)
select ca,sum(da)da
from (
select ca,da from t_A
union all
select ca,da from t_B
)t
group by ca
Ca与Cb列中的数据都是唯一的
(select ca,cb from tb_a
union all
select * from tb_b)K
group by ca
select CC,Sum(Dc) DC from
(select Ca CC,Da DC from t_A union all
select Cb,Db from t_B B ) C Group by CC
union
select Cb as Cc,Db as CC from t_B
from (
select ca,da from t_A
union all
select ca,da from t_B
)t
group by ca
以外的还有吗?不用sum,不用union