Mutual friends sql with join (Mysql)

Question

I have two tables

users table:

id|name

user_relationships

id | user_id | friend_id

and want to ge

Answer 1

You could try something like this:

select id, name from users where id in 
    (select friend_id from user_relationships where user_id = @user1_id and friend_id in 
        (select friend_id from user_relationships where user_id = @user2_id)
    )

This should return all mutual friends of users with the IDs @user1_id and @user2_id. It's not tested yet, but should provide a starting point...