加入MySQL以获取多个表数据 [英] Joins In MySQL for fetching multiple tables data

问题描述

我有两个表用户并关注.我想编写视图，以便它将获取特定用户的所有详细信息以及这两个额外的列，作为关注者计数和关注者计数别名.

I have two table user and follow. I want to write view such that it will fetch all details of particular user along with that two extra column as follower count and followee count alias.

例如user id = 11，然后是用户表中的所有详细信息，再加上followcount 1和count1

eg. user id=11 then all details from user tables plus followcount 1 and followed count1

推荐答案

SELECT u.id, 
       u.userid, 
       u.name, 
       u.mobile, 
       (SELECT Count(*) 
        FROM   follow f 
        WHERE  f.followerid = u.userid) AS follower, 
       (SELECT Count(*) 
        FROM   follow f 
        WHERE  f.followeeid = u.userid) AS followee 
FROM   users u 

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