使用JOIN获取有关两个用户的信息

I got a problem. I am making a Private messages system now, and I need to get user and his rank info to print it on screen. So I do JOIN

我遇到了问题。我现在正在建立一个私人消息系统,我需要获得用户和他的排名信息,以便在屏幕上打印它。所以我加入了

SELECT 
   private_messages.from    as `from`,
   private_messages.to      as `to`,
   private_messages.theme   as `theme`,
   private_messages.date    as `date`,
   private_messages.message as `message`,
   users.username           as `username`,
   users.id                 as `user_id`,
   private_messages.id      as `pm_id`,
   ranks.style              as `style`,
   ranks.rank_name          as `rank_name`
FROM `private_messages` 
LEFT JOIN `users` ON private_messages.from = users.id
LEFT JOIN `ranks` ON users.rank            = ranks.id
WHERE   private_messages.id=? LIMIT 1

But the problem is that I get only info about user 'from' (who sended a message) and dont get rank and other things about user 'to' (who received a message) and I need his info too and don't know what to do, can anyone help me? :)

但问题是,我只获得有关用户'来自'(谁发送了一条消息)的信息,并且没有得到关于用户'到'(谁收到消息)的等级和其他事情,我也需要他的信息而且不知道是什么要做,谁能帮帮我? :)

1 个解决方案

#1

If you want infor about two user you must join two time the table user one for user_from an one for user_to ...

如果你想要关于两个用户,你必须加入两次表用户一个user_from一个用户user_to ...

this is just a suggestion for getting info for two users

这只是获取两个用户信息的建议

SELECT 
    private_messages.from as `from`,
    private_messages.to as `to`,
    private_messages.theme as `theme`,
    private_messages.date as `date`,
    private_messages.message as `message`,
    users.username as `username`,
    users_to.username as `username_to`
    users.id as `user_id`,
    private_messages.id as `pm_id`,
    ranks.style as `style`,
    ranks.rank_name as `rank_name`
    FROM `private_messages` 
    INNER JOIN `users` ON private_messages.from = users.id
    INNER JOIN `users` as user_to ON private_messages.to = users.id
    LEFT JOIN `ranks` ON users.rank = ranks.id
    WHERE   private_messages.id=? LIMIT 1

1 个解决方案

#1

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