求一个SQL语句!!!
A 表
ID NAME
12
13B 表
ID SID
12 z123
12 3242
12
13 x4523
13
13 4322
select a.id,b.sid from 表A a,表B b where a.id = b.id and b.id is not null
结果如下:
12 Z123
12 3242
13 x4523
13 4322
我希望结果是:
12 Z123
13 x4523
或者
12 Z123
13 4322
或者
12 3242
13 4322
或者
12 3242
13 x4523 如何实现,我比较菜,大家给帮一下!
A 表
ID NAME
12
13B 表
ID SID
12 z123
12 3242
12
13 x4523
13
13 4322
select a.id,b.sid from 表A a,表B b where a.id = b.id and b.id is not null
结果如下:
12 Z123
12 3242
13 x4523
13 4322
我希望结果是:
12 Z123
13 x4523
或者
12 Z123
13 4322
或者
12 3242
13 4322
或者
12 3242
13 x4523 如何实现,我比较菜,大家给帮一下!
(SELECT A.ID, B.SID FROM
CSDN.TABLEA A
INNER JOIN
(SELECT * FROM CSDN.TABLEB WHERE SID IS NOT NULL) B
ON A.ID = B.ID) C
GROUP BY ID;
---------- --------------------------------------------------
12 z123
13 x4523SELECT ID, MIN(SID) AS SID FROM
(SELECT A.ID, B.SID FROM
CSDN.TABLEA A
INNER JOIN
(SELECT * FROM CSDN.TABLEB WHERE SID IS NOT NULL) B
ON A.ID = B.ID) C
GROUP BY ID;
---------- --------------------------------------------------
12 3242
13 4322还有就是用case来做