Facebook FQL Query OR

Question

I am trying to create an OR clause in FQL query.

Here is my query :

SELECT post_id, message, permalink, likes, actor_id, created_time FROM stream  WHERE 
(source_id = xxx1 AND message != '' AND actor_id = xxx2) 
OR 
(source_id = xxx2 AND actor_id = xxx1) 

Globally I want to retrieve all the messages between 2 Facebook users. If I remove the OR clause I do receive messages in one way but adding the OR removes every messages I have as if the '(' do not work.

If you need to test this query please go on : http://developers.facebook.com/tools/explorer and create and access token with the read_stream permission (Extended Permissions)

I also wanted to use a UNION but it is not supported by FQL. Maybe I could use FQL multiple queries but I was still blocked by the UNION missing.

Thank you for your help.

Answer 1

You can use sub queries to achieve the desired result like this:

SELECT post_id, message FROM stream 
WHERE 
    (
      post_id in (select post_id from stream where actor_id = uid0 and source_id  = uid1) 
    or  
      post_id in (select post_id from stream where actor_id = uid1 and source_id  = uid0)
    ) 
    and message != ''

Answer 2

The answer provided by complex857 is correct but I would like to add some information. To make this query work you must add a LIMIT / OFFSET clause to your query.

SELECT post_id FROM stream
    WHERE 
        (post_id IN (SELECT post_id FROM stream WHERE source_id = uid0 AND actor_id = uid1 LIMIT 1000 OFFSET 0)
            OR 
        post_id IN (SELECT post_id FROM stream WHERE source_id = uid1 AND actor_id = uid0 LIMIT 1000 OFFSET 0))
    AND message != '';

Hope this will help :)