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如何在mysql中连接表_Mysql_Sql_Inner Join - Fatal编程技术网

如何在mysql中连接表

如何在mysql中连接表,mysql,sql,inner-join,Mysql,Sql,Inner Join,我有两个表格如下: users -id (primary key, AUTO_INCREMENT) -username (varchar) -password (varchar) users_messages -id (primary key, AUTO_INCREMENT) -message (text) -fk sender_id (int) -fk receiver_id(int) -sent_date(datetime) -is_read(tinyint) Mes

我有两个表格如下:

users
 -id (primary key, AUTO_INCREMENT)
 -username (varchar)
 -password (varchar)

users_messages
 -id (primary key, AUTO_INCREMENT)
 -message (text)
 -fk sender_id (int)
 -fk receiver_id(int) 
 -sent_date(datetime)
 -is_read(tinyint)
Message                Sender            Receiver
Message 1 testing      john              sonam
Message 2 testing      meena             shenaz
users_消息中的两个外键引用相同的表,即users 我想编写一个sql查询以获得如下输出:

users
 -id (primary key, AUTO_INCREMENT)
 -username (varchar)
 -password (varchar)

users_messages
 -id (primary key, AUTO_INCREMENT)
 -message (text)
 -fk sender_id (int)
 -fk receiver_id(int) 
 -sent_date(datetime)
 -is_read(tinyint)
Message                Sender            Receiver
Message 1 testing      john              sonam
Message 2 testing      meena             shenaz
我该怎么做?我需要从users\u messages表中获取所有消息,发送方id和接收方id被users表中的username列替换

编辑 解决方案:

SELECT m.id, m.message, s.username, r.username FROM users_messages m 
INNER JOIN users s ON m.sender_id = s.id
INNER JOIN users r ON m.receiver_id = r.id
试一试