從MySQL返回最新消息？

Question

我需要在以下查詢中添加一個聯接，該聯接將messages_message表聯接到messages_threads表，並從messages_messages中的最新行返回“ body”和“ time”字段，其中messages_message.threadid = messages_threads.id。

抱歉，這真令人困惑，我不知道該怎么說。 這是我當前的查詢-正確提取除“正文”和“時間”字段以外的所有內容。

SELECT 
    messages_threads.id AS threadid, messages_threads.name AS recipientsname, 
    senderid, username AS sendername, pictures.url AS senderpicture
FROM 
    messages_recipients
    JOIN messages_threads 
        ON messages_threads.id = messages_recipients.threadid
    JOIN users 
        ON users.id = messages_threads.senderid
    JOIN pictures 
        ON messages_threads.senderid = pictures.userid 
        AND pictures.profile = 1
WHERE messages_recipients.userid = $userid

Answer 1

您可以添加messages_message表的子查詢，該查詢將為每個線程返回1行。 例如：

SELECT 
    messages_threads.id AS threadid, messages_threads.name AS recipientsname, 
    senderid, username AS sendername, pictures.url AS senderpicture
FROM 
    messages_recipients
    JOIN messages_threads ON messages_threads.id = messages_recipients.threadid
    JOIN users ON users.id = messages_threads.senderid
    JOIN pictures ON messages_threads.senderid = pictures.userid AND pictures.profile = 1
    JOIN ( SELECT threadid, MAX(id) AS postid FROM messages_message GROUP BY threadid ) t ON message_threads.id = t.threadid
    JOIN messages_message ON t.threadid = messages_message.threadid AND t.postid = messages_message.id
WHERE messages_recipients.userid = $userid

Answer 2

我認為您也需要按身體和時間分組...或者您還可以指定您的查詢..