Question

CREATE TABLE `social_activity_stream` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  `social_actor_id` int(11) NOT NULL,
  `social_activity_id` bigint(20) NOT NULL,
  `social_activity_type_id` int(11) NOT NULL,
  `social_share_policy_id` int(11) DEFAULT NULL,
  `social_user_friend_id` bigint(20) DEFAULT NULL,
  `date_created` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  `date_read` datetime DEFAULT NULL,
   PRIMARY KEY (`id`))

Every social actor creates a social activity, with share policy PUBLIC, PRIVATE, FRIENDS
Lets say there are 3 actors:
A, B, C
They’re friends

An activity shared by A with FRIENDS (policy) would create 3 rows in the table:

• One for A [A, A TEXT POST, FRIENDS, NULL]
• One for B [B, A TEXT POST, FRIENDS, A->B]
• One for C [C, A TEXT POST, FRIENDS, A->C]

B wants to browse A’s activity stream:
Here is the pseudo query:

• GET PUBLIC ACTVITIES by A’ stream
• GET PRIVATE ACTIVITIES by A’stream with FriendId = A->B
• GET FRIENDS ACTIVITIES by A’stream but only if that activity exists
  in B’s stream (otherwise it could be for a friend D of A who is not
  friend of B)

Any idea this can be done in a single query?

Answer 1

Duh, that was simple. Poor question indeed.

SELECT a.*
from social_activity_stream a INNER JOIN social_activity_stream b USING(social_activity_id) WHERE 
a.social_actor_id = [user_id] and b.social_actor_id = [friend_id];