Question

EDIT by:lawrence.

我现在谈谈正确的问题。

select * from users, friends where (users.id=friends.user_id1 and friends.user_id2=$profileID) or (users.id=friends.user_id2 and friends.user_id1=$profileID)

回答问题

我需要帮助加入我的朋友和用户表的成果。

这就是我的朋友们认为的。

id     user_id1     user_id2   
1   |  2         |  3  
1   |  2         |  4  
1   |  2         |  5  
1   |  6         |  2

www.un.org/Depts/DGACM/index_spanish.htm 用户表

id    name  
2  |  sarah  
3  |  emma  
4  |  lawrence  
5  |  cynthia  
6  |  suzie

I could easily just have two rows for each relation and do a simple query.
But i prefer having one row per relation,

So lets assume that we are watching page member.php?profile=2
and there is a list of friends, what does the query look like.

如果两行各有关系,但一意想这样做,则罚款。

SELECT * FROM friends, users WHERE friends.user_id1 = $profileID AND friends.user_id2 = users.id ORDER BY friends.id DESC LIMIT 16

你们是谁? 类似情况

SELECT * FROM friends,users WHERE friends.user_id1 = $profileID AND ALSO WHERE friends.user_id2 = $profileID AND THEN GET FROM users WHERE users.id = friends.user_id1 AND ALSO WHERE users.id = friends.user_id2

我希望我明确表示:

Answer 1

我不敢肯定我会理解你的问题,但会赢得这样的??

SELECT * FROM friends, users where friends.user_id1 = $profileID or friends.userid2 = $profileID and users.id = friends.user_id1 or  users.id = friends.user_id2

Answer 2

页: 1

http://www.w3schools.com/sql/sql_join_left.asp

提早:凭您的交叉参比表,而不是用一栏id子,你就可以形成一个复杂的钥匙。

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