MYSQL CASE WHEN PROBLEM

Question

    SELECT `profiles`.* 
    FROM `profiles` 
    INNER JOIN `friendships` 
    ON `profiles`.id = `friendships`.(CASE WHEN friendships.profile_id = 1
    THEN`friend_id` ELSE `profile_id` END)

How can i make the inner join like profile.id = friendships.(here will select the one key that is needed) but it doesnt work. please help :P

it cant be:

         `profiles`.id =  (CASE WHEN friendships.profile_id = 1
         THEN `friendships`.`friend_id` ELSE `friendships`.`profile_id` END)

Answer 1

SELECT `profiles`.* 
FROM `profiles` 
INNER JOIN `friendships` 
ON `profiles`.id = (CASE WHEN friendships.profile_id = 1
THEN friendships.`friend_id` ELSE friendships.`profile_id` END)

Answer 2

How about

SELECT  `profiles`.* 
  FROM `profiles` 
  INNER JOIN `friendships`
   ON (profiles.id = friendships.profile_id AND NOT (profile_id = 1))
       OR ((profiles_id =friendships.friend_id) AND (profile_id = 1))