幫助count（）;

Question

我有2張桌子。 一個叫做Video，另一個叫做ThumbsUp。

Video -> Id, Path, Thumbnail, Profile 

ThumbsUp -> Id, Owner, Video 

我需要拉每個視頻記錄WHERE PROFILE = 2， 而COUNT(ThumbsUp.Id)喜歡的每個視頻的數量， 即使該視頻沒有任何豎起大拇指。

任何幫助表示讚賞。 。 。

Answer 1

SELECT Video.Id, COUNT(ThumbsUp.Video) 
FROM 
    Video LEFT JOIN ThumbsUp ON Video.Id = ThumbsUp.Video 
WHERE Video.Profile = 2 
GROUP BY Video.Id 

Answer 2

SELECT V.*, COUNT(T.id) FROM Video V 
OUTER JOIN ThumbsUp T ON T.Video = V.id 
WHERE V.profile == 2; 

編輯：添加外連接

Answer 3

SELECT v.*, count(tu.id) 
     FROM video v 
     LEFT JOIN ThumbsUp tu ON tu.video_id = v.id 
    WHERE v.profile = 2 
    GROUP BY v.id