從三個表獲取數據的mysql加入

Question

我在我的數據庫中的三個表

1.Users（ID，用戶名）

2.Stories（ID，USER_ID，內容）這裏是user_id關鍵forigen指Users表id

3.Comments（ID，USER_ID，story_id，評論）這裏user_id是forigen鍵指Users表id和story_id是forigen鍵指Stories表id

我需要從Stories表中獲取的故事名單與上storie筆者

下面的那個帖子和用戶名評論總數是我對於

SELECT stories.id,stories.content,COUNT(stories.id) as totalcomment 
FROM stories 
JOIN comments 
ON stories.id=comments.story_id GROUP BY stories.id 

我會得到總查詢

Answer 1

的每個崗位的評論，但不能取storie作者（從用戶表即用戶名）的用戶名試試這個：

SELECT stories.id,stories.content,COUNT(stories.id) as totalcomment, Users.username 
FROM stories, Users, comments 
WHERE stories.id=comments.story_id 
AND stories.user_id = Users.id 
GROUP BY stories.id 

或者與加盟：

SELECT stories.id,stories.content,COUNT(stories.id) as totalcomment, Users.username 
FROM stories 
JOIN comments ON stories.id=comments.story_id 
JOIN users ON stories.user_id = Users.id 
GROUP BY stories.id 

希望這個作品。

Answer 2

SELECT s.id,s.content,COUNT(c.story_id) as totalcomment, u.username 
FROM stories s LEFT JOIN comments c ON (s.id=c.story_id) 
LEFT JOIN users u ON (s.user_id = u.id) 
GROUP BY s.id