如何合并2个复杂的mysql查询

Question

因此，我有两个MySQL查询，如果我有结合的知识，我会但不知道，这就是为什么我转向“ SO”的原因，在那种情况下，我没有尝试任何事情，因为它超出了我的范围。 我想将所有查询合并为一个查询，如果无法实现，请告诉我。

查询一个“这将选择您所有的朋友帖子，包括您的帖子”：

"SELECT b.*, c.photo, d.name, e.status 
FROM post b 
INNER JOIN profile c 
INNER JOIN user d 
INNER JOIN user_friendship e 
ON b.from_user = c.user_id 
AND b.from_user = d.id 
AND e.friend_id = b.from_user 
WHERE e.status = :status 
AND e.user_id = :id
ORDER BY b.id DESC LIMIT 20"

查询两个“这将选择您要发布的所有人员”：

"SELECT b.*, c.photo, d.name, e.status
FROM post b
INNER JOIN profile c 
INNER JOIN user d 
INNER JOIN user_follower e 
ON b.from_user = c.user_id 
AND b.from_user = d.id 
AND e.to_id = b.from_user 
WHERE e.status = :status 
AND e.who_id = :id
ORDER BY b.id DESC LIMIT 20"

我结合了这些，但仅与php结合。 我想将两者合并在一个MySQL查询中 。 提前致谢

Answer 1

SELECT *
FROM
  (SELECT b.*,
          c.photo,
          d.name,
          e.status
   FROM post b
   INNER JOIN profile c
   INNER JOIN USER d
   INNER JOIN user_friendship e ON b.from_user = c.user_id
   AND b.from_user = d.id
   AND e.friend_id = b.from_user
   WHERE e.status = :status
     AND e.user_id = :id LIMIT 20
   UNION SELECT b.*,
                c.photo,
                d.name,
                e.status
   FROM post b
   INNER JOIN profile c
   INNER JOIN USER d
   INNER JOIN user_follower e ON b.from_user = c.user_id
   AND b.from_user = d.id
   AND e.to_id = b.from_user
   WHERE e.status = :status
     AND e.who_id = :id LIMIT 20 ) MainQuery
ORDER BY id DESC

Answer 2

SELECT b.*, c.photo, d.name, e.status, "P" 
FROM post b 
INNER JOIN profile c 
INNER JOIN user d 
INNER JOIN user_friendship e 
ON b.from_user = c.user_id 
AND b.from_user = d.id 
AND e.friend_id = b.from_user 
WHERE e.status = :status 
AND e.user_id = :id
ORDER BY b.id DESC LIMIT 20
UNION
SELECT b.*, c.photo, d.name, e.status, "F"
FROM post b
INNER JOIN profile c 
INNER JOIN user d 
INNER JOIN user_follower e 
ON b.from_user = c.user_id 
AND b.from_user = d.id 
AND e.to_id = b.from_user 
WHERE e.status = :status 
AND e.who_id = :id
ORDER BY b.id DESC LIMIT 20

通过额外的列，您可以看到行的来源（P =发布，F =跟随）

请记住，联合将删除重复的行。 如果要查看所有行，请使用UNION ALL