表A (c1,c2,c3)
表B(c1,c2)
A表数据如下:
c1 c2 c3
1 2 3
1 3 4
1 6 4
2 2 1
2 3 8
B表数据如下
c1 c2
2 3我现在要算count(c1)条件
是c2 =表B中的C1和C2(2,3)中的数据,然后是group by c1
得到的结果为
b.c1 b.c2 count(c1)
2 3 2
很急
表B(c1,c2)
A表数据如下:
c1 c2 c3
1 2 3
1 3 4
1 6 4
2 2 1
2 3 8
B表数据如下
c1 c2
2 3我现在要算count(c1)条件
是c2 =表B中的C1和C2(2,3)中的数据,然后是group by c1
得到的结果为
b.c1 b.c2 count(c1)
2 3 2
很急
1 A中c2 =表B中的C1
2 C2(2,3)中的数据,然后是group by c1--这里不知道什么意思?
是c2 =表B中的C1和C2(2,3)中的数据
就是SELECT COUNT(C1) FROM A WHERE EXISTS(SELECT 1 FROM B WHERE C2=B.C1)
AND EXISTS(SELECT 1 FROM B WHERE C2=B.C2)
(
c1 int,
c2 int,
c3 int
)
insert into A
select 1,2,3 union all
select 1,3,4 union all
select 1,6,4 union all
select 2,2,1 union all
select 2,3,8
select * from A
Create table B
(
c1 int,
c2 int
)
insert into B
select 2,3
select B.*,[count(c1)] from B inner join (select c1,count(c1) as [count(c1)] from A where c2 in((select c1 from B) union all (select c2 from B)) group by c1)t
on B.c1=t.c1
是c2 =表B中的C1和C2(2,3)中的数据
就是SELECT COUNT(C1) FROM A WHERE EXISTS(SELECT 1 FROM B WHERE C2=B.C1)
AND EXISTS(SELECT 1 FROM B WHERE C2=B.C2)"
"但是我不知道怎么把b.c1 b.c2这两个字段取出来"
把你取出的结果跟B表连接
from b left join a on a.c2=b.c2
group by b.c1,b.c2