Is it possible to add a join inside a join for e.g
(dbFriends LEFT JOIN dbPosts_share ON dbPosts_share.share_user_id = dbFriends.friend_id)
(dbPosts.username_id = dbFriends.my_id
dbPosts.username_id = dbFriends.friend_id)
joins are serial
start with a table, join a second table, then join another table, then join another table, etc.
and you're still messing around with ORs, aren't you