Question

在一个社交网络项目中，我希望得到朋友的随机朋友，以便像Facebook那样向用户推荐。建议用户的数量是动态的。但我们的表格字段如下：

inviter_id，friend_id，status

因此user id可以在inviter_id或friend_id中，status 2表示朋友请求已被接受且他们当前是朋友。

任何人都可以帮我解决一个不错的解决方案吗？

我已经拥有了一个，当它变得越来越大时，它肯定会减慢网站的速度。

提前致谢。

Answer 1

这样的事情可能会这样做。

SELECT DISTINCT id FROM (
    (SELECT t1.inviter_id as id FROM TableName t1 LEFT JOIN TableName t2 ON t1.friend_id = t2.inviter_id WHERE t1.status = 1 AND t2.status=1 AND t2.friend_id = UserId)
    UNION
    (SELECT t1.inviter_id as id FROM TableName t1 LEFT JOIN TableName t2 ON t1.friend_id = t2.friend_id WHERE t1.status = 1 AND t2.status=1 AND t2.inviter_id = UserId)
    UNION
    (SELECT t1.friend_id as id FROM TableName t1 LEFT JOIN TableName t2 ON t1.inviter_id = t2.inviter_id WHERE t1.status = 1 AND t2.status=1 AND t2.friend_id = UserId)
    UNION
    (SELECT t1.friend_id as id FROM TableName t1 LEFT JOIN TableName t2 ON t1.inviter_id = t2.friend_id WHERE t1.status = 1 AND t2.status=1 AND t2.inviter_id = UserId)
) as temp WHERE id != UserId AND NOT EXISTS (SELECT * FROM TableName WHERE (friend_id = id AND inviter_id=UserId) OR (inviter_id = id AND friend_id=UserId))

（将表名替换为您的表的名称，将UserId替换为目标用户/变量）。

链接到我的测试/示例：http://sqlfiddle.com/#!2/ddbec/2

使用此表结构获取PHP和MYSQL中的朋友的朋友

1 个答案: