Question

I have 3 tables on my database :

Users :

id  ------- username
1            user1  
2            user2

writers

id  ------- name
4           writer4
5           writer5 
8           writer8

Following :

user_id  -----  follow  
1               5
1               8
2               5

so, now User1 follows writer5 and writer8 , and user2 follows writer5

I’m login to my app as user1 , when I go to the writers page I get list of all writers in the database ..
I just want to show in front of each writer whether I’m following this writer or not ..

List Writers Page example:

writer4     :follow
writer5     :unfollow (i'm following him now)
writer8     :unfollow (i'm following him now)
writer100     :follow 

my question is : Is there a query to get the full list of writers and give me a value=0 if I’m not (as user1) following this writer

any ideas ?
thanks ..

Answer 1

You need to use CROSS JOIN in order for user to get all writers.

SELECT b.name,if(c.userid is null, 'follow', 'unfollow') result
FROM users a
        CROSS JOIN writers b
        LEFT JOIN following c
          on a.id = c.userid AND
             b.id = c.follows
WHERE a.id = 1

SQLFiddle Demo