空結果左加入

Question

我有一個奇怪的結果從一個MySQL查詢來：

如果我使用

SELECT cbe.id, cbe.user_id, cbe_profile_gender ,bud.status,cbe.avatar 
FROM findme as cbe 
LEFT JOIN findme_buddylist as bud ON cbe.user_id = bud.userid 
WHERE cbe.user_id<>2122 
AND cbe.avatar != "" 
AND bud.status != "2" 

我沒有得到任何結果，因爲表ade39_findme_buddylist是空

但如果我刪除行：

AND bud.status != "2" 

我得到的結果顯示bud.status = NULL

出了什麼問題？

謝謝！

Answer 1

條件上的LEFT JOIN的秒表應該是in子句中：

SELECT cbe.id, cbe.user_id, cbe_profile_gender ,bud.status,cbe.avatar 
FROM ade39_findme cbe LEFT JOIN 
    ade39_findme_buddylist bud 
    ON cbe.user_id = bud.userid and bud.status <> 2 
WHERE cbe.user_id <> 2122 AND cbe.avatar <> '';