Question

让我们说:

table users(id, name, ..)
table friends(uid, fid)

我怎样才能有33456个用户身份朋友?

 SELECT fid idd, name
    FROM users, 
         friends 
WHERE uid = 33456
    AND fid = id

但是会给我意想不到的结果

Answer 1

SELECT  id, fid, name
FROM users,friends where users.id=friends.fid
WHERE users.id = 33456

Answer 2

SELECT  id, fid, name
FROM users
INNER JOIN friends ON users.id=friends.fid
WHERE users.id = 33456

Answer 3

select id,name from users where id in (select fid from friends where uid=33465)

Answer 4

这将返回所有身份, 以您朋友的名字。

SELECT b.fid, c.name
FROM users a INNER JOIN friends b ON a.id = b.uid
     INNER JOIN users c on b.fid = c.id
WHERE a.id = 33456

Answer 5

SELECT u.name,u.id 
FROM users u 
WHERE u.id IN 
(
SELECT f.fid 
FROM users u INNER JOIN friends f ON u.id = f.fid 
WHERE f.uid = 33456 
)