Get data from one table filtering it by other table in MYSQL

Question

Table 1:

userid name
1      Dharam
2      James
3      Ramesh
4      David

Table 2:

follower(id) following(id)
1            2
2            1
2            3
3            4

Here, I have Table 1 for all users and Table 2 for who is following whom.

I want to get result as

Show the users from 'Table 1' WHERE 'Table 1' users should not be already following the same person

Means, Get users whom user 1 is not following FROM Table 1 filtered by Table 2

Result:

3
4

Another Twitter-like problem? Search SO there are several similar questions — AlexL, Nov 14 '14 at 08:45

score 0 · Accepted Answer · answered Nov 14 '14 at 08:47

0

Use: inner query

SELECT * from users WHERE user_id NOT IN (
               SELECT user_id_foreign_key FROM follow_details)

answered Nov 14 '14 at 08:47

Pratik Joshi

**Thank You**, for Your answer. But, I want every users except the users whom one user is following. But your query is giving the user who is not following anyone. – Dharmendra Jadon Nov 14 '14 at 09:20

score 0 · Answer 2 · edited Nov 14 '14 at 08:57

0

Or you can do it with a join:

 SELECT t1.userid, t2.follower
 FROM tbl1 AS t1 
      LEFT JOIN tbl2 ON t1.userid = t2.follower
 HAVING follower IS NOT NULL

edited Nov 14 '14 at 08:57

answered Nov 14 '14 at 08:50

AlexL

2 Answers2