我第一次使用。选择内部连接表ID vb
SELECT classroom .cls_id,
classroom.cls_name,
u1.users_id as users_id1,
u2.users_id as users_id2
FROM classroom
INNER JOIN clsown
ON clsown.cls_id = classroom .cls_id
INNER JOIN users AS u1
ON clsown.users_id = u1.users_id
INNER JOIN users AS u2
ON clsown.users_id = u2.users_id
我得到这个:
cls_id cls_name users_id1 users_id2
1 -------- room1 ------- 1 --------- 1
1 -------- room1 ------- 2 --------- 2
2 -------- room2 ------- 3 --------- 3
2 -------- room2 ------- 4 --------- 4
我希望看到
cls_id cls_name users_id1 users_id2
1 -------- room1 ------- 1 --------- 2
2 -------- room2 ------- 3 --------- 4
我不知道该怎么办内连接。我究竟做错了什么?
感谢您的回答。
哪里都是2'users_id'来自哪里?你的查询限制了在'clsown'和'u1'中这些字段必须相等的地方,所以我很困惑你想让它们与众不同。 – 2013-03-26 15:46:30
https://www.dropbox.com/s/jhiftrhrt0i0a9w/kkk.JPG – Harajukuzz 2013-03-26 16:34:35
@Harajukuzz你只有2个用户?你使用的是什么RDBMS? – Taryn 2013-03-26 17:08:30