與條件添加一個額外的列在聯合查詢

Question

我已經存儲了用戶的帖子在表中調用領域帖子

id 
userid 
posttitle 
status 

我已經存儲了用戶收藏的帖子在fav_posts表的字段

id 
post_id 
userid 

帖子表

代碼：

id userid  posttitle status 
1 1200 title 1 Active 
2 1200 title 2 Active 
3 1200 title 3 Active 
4 1200 title 4 Active 
5 1201 title 5 Active 
6 1201 title 6 Active 
7 1201 title 7 Active 
8 1201 title 8 Active 

個

Fav_posts表 代碼：

id post_id  userid 
1 1 1200 
2 2 1201 
3 5 1202 
4 6 1202 
5 6 1201 
6 8 1201 
7 8 1200 
8 7 1200 

現在 如果我輸入的用戶 我得的是存在於兩個表 的記錄，但應該只來過一次 並設有獨立的字段值 即 如果我進入ID爲1200 結果應該是

代碼：

post_id  title post_came_in 
1 title 1 BOTH 
8 title 8 FAV 
7 title 7 FAV 
2 title 2 MYPOST 
3 title 3 MYPOST 
4 title 4 MYPOST 

我能夠列出聯盟榜首 但我不知道如何納入結果檢查後成立的第三個字段，發現相同的記錄來在我的職位和崗位最愛

我同時使用下面的查詢來獲取聯盟結果

SELECT post_id,title 
FROM posts 
LEFT JOIN fav_posts ON posts.id = fav_posts.post_id WHERE fav_posts.userid = 1200 
UNION ALL 
SELECT id AS post_id,title FROM posts WHERE userid = 1200 

請告訴我，我怎麼能在查詢

問候一個檢查標準 ANEES

Answer 1

SELECT post_id, title, 'FAV' AS `post_came_in` FROM posts LEFT JOIN fav_posts ON posts.id = fav_posts.post_id WHERE fav_posts.userid = 1200 
UNION ALL 
SELECT id AS post_id, title, 'MYPOST' AS `post_came_in` FROM posts WHERE userid = 1200 

Answer 2

SELECT 
post_id, title, 
CASE WHEN posts.id IS NULL THEN 'FAV' 
     WHEN fav_posts.id IS NULL AND posts.id IS NOT NULL THEN 'MYPOST' 
     ELSE 'BOTH' 
END post_came_in 
FROM 
posts FULL JOIN fav_posts ON posts.id = fav_posts.post_id 
WHERE 
(fav_posts.userid = 1200) OR (posts.userid = 1200)