從多個子表中選擇

Question

我有一張名爲meeting的表，一個名爲meeting_permissions。後者存儲用戶參加任何特定會議的內容。我還有其他表格：註釋，討論，結論和主題，存儲會議記錄的具體項目。我想要做的是獲取特定用戶參加的所有會議，以及所有相關的註釋，討論，結論和主題。這是我想出的：

SELECT * FROM meeting WHERE id IN 
(SELECT meeting_id FROM meeting_permissions WHERE user_id = $user) 
LEFT JOIN conclusion ON meeting.id = conclusion.meeting_id 
LEFT JOIN discussion ON meeting.id = discussion.meeting_id 
LEFT JOIN note ON meeting.id = note.meeting_id 
LEFT JOIN topic ON meeting.id = topic.meeting_id 

這對我不起作用。它在第二次左連接斷開。我能做些什麼來解決這個問題？

Answer 1

你加入對你的子選擇，而不是你的主要會議桌：

SELECT 
    meeting.*, 
    conclusion.* 
    discussion.*, 
    note.*, 
    topic.* 
FROM meeting 
    LEFT JOIN conclusion ON meeting.id = conclusion.meeting_id 
    LEFT JOIN discussion ON meeting.id = discussion.meeting_id 
    LEFT JOIN note ON meeting.id = note.meeting_id 
    LEFT JOIN topic ON meeting.id = topic.meeting_id 
WHERE meeting.id IN 
    (SELECT mp.meeting_id FROM meeting_permissions mp WHERE mp.user_id = $user)