我在数据库和查询中使用了三个表，我应该结合使用。表格如下：
表格消息：
message_id | msg_id | conv_id | text | user_id
--------------------------------------------------------------
1 | 1 | 1 | hi | 12
2 | 1 | 1 | Thanks | 14
3 | 2 | 4 | helo | 21
表格对话：
conv_id | msg_id | conv_id | subject | user_id | text
------------------------------------------------------------------------
1 | 1 | 1 | sub1 | 12 | Hi to all
2 | 1 | 1 | sub1 | 14 | Hi to all
3 | 2 | 4 | sub3 | 21 | reply2
具有msg_id的两个表是常见的，
我的预期结果是，
来自会话表组的msg_id，
来自messsage表message.msg_id = conversation.msg_id
conv_id | msg_id | conv_id | subject | text
-----------------------------------------------------------------
1 | 1 | 1 | sub1 | Hi to all
1 | 1 | 1 | sub1 | hi
2 | 1 | 1 | sub1 | thanks
3 | 2 | 4 | sub3 | helo
我的查询是
SELECT *
FROM mailbox_message m1
LEFT JOIN mailbox_conversation m2 ON m1.conversation_id=m2.conversation_id
WHERE m2.msg_id='1'
ORDER BY m1.created DESC
我的查询返回以下内容
conv_id | msg_id | conv_id | subject | text
-----------------------------------------------------------------
1 | 1 | 1 | sub1 | Hi to all
2 | 1 | 1 | sub1 | Hi to all
1 | 1 | 1 | sub1 | hi
2 | 1 | 1 | sub1 | thanks
3 | 2 | 4 | sub3 | helo