mysql排序发送和接收的消息

Question

我的数据库中有一个表

SenderId    ReceiverId  Message         DateAndTime
int(11)     int(11)     varchar(200)    DATETIME

我想为对话风格的已登录用户排序所有消息。记录的用户之间的消息说UserA和UserB，UserC应该如下所示：

UserA   UserB   Sent
UserA   UserB   Sent
UserB   UserA   Received

UserA   UserC   Sent
UserC   UserA   Received
UserA   UserC   Sent

UserD   UserA   Receied
UserA   UserD   Sent

我已经尝试过这个查询，但结果并不像我期望的那样

SELECT * FROM messages WHERE SenderId like ? or ReceiverId like ? order by senderId, dateAndDate;

Answer 1

这可能有用。它不是按时间排序，而是由参与者排序。

SELECT CONCAT(LEAST(SenderID, ReceiverId), '-', GREATEST(SenderID, ReceiverId)) AS conversation
  , SenderID, ReceiverID, Message, DateAndTime
FROM messages
WHERE SenderID = ? OR ReceiverId =?
ORDER BY conversation, DateAndTime DESC;

Answer 2

这应该可以解决问题。

SELECT SenderId, ReceiverId, Message, DateAndTime, CASE WHEN SenderId=1 THEN ReceiverId Else SenderId END as Optional from messages where SenderId = 1 or ReceiverId=1 order by Optional, DateAndTime desc;

假设Logged UserID为1，请改用占位符。