我如何在MySQL中使用外键进行查询？ [英] How can I query using a foreign key in MySQL?

问题描述

  users表
 = =================== 
 id name status_id 
 1 Bobby 3 
 2 James 2 
  

和

 状态表
 ============= 
 id值
 1等待
 2已核准
 3其他
  

status_id被设置为状态表中id的外键约束。我的查询看起来像这样：

$ p $ SELECT
FROM`users`
WHERE`status_id` = 2;

当我显示 $ row ['status_id'] 它会输出 2 ，但是我希望它显示为 Approved ，相反，最好的方法是什么

选择你*，s。*
FROM用户u
内部连接状态在u.status_id = s.id
WHERE u.status_id = 2


Right now I have a small database with two tables that look something like this:

    users table
    ====================
    id  name   status_id
    1   Bobby  3
    2   James  2

and

    statuses table
    =============
    id  value
    1   Waiting
    2   Approved
    3   Other

status_id is setup as a foreign key constraint to id from the statuses table. My query looks something like this:

SELECT *
FROM `users`
WHERE `status_id` = 2";

When I display $row['status_id'] it outputs 2 but I would like it to display as Approved instead, what is the best way to accomplish this?

解决方案

SELECT u.*, s.*
FROM users u
    inner join statuses s on u.status_id = s.id
WHERE u.status_id = 2

这篇关于我如何在MySQL中使用外键进行查询？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！