Answer 1

Answer 2

SELECT distinct TOP(20) e.*, u1.UserName As Sender,
u2.UserName As Receiver, u1.Avatar AS SenderPic  
FROM Friends f INNER JOIN Users u 
ON(u.Id = f.SenderId OR u.Id = f.ReceiverId) AND State = 'ok' 
INNER JOIN Events e 
ON(f.SenderId = e.SenderId OR f.SenderId = e.ReceiverId 
OR f.ReceiverId = e.SenderId OR f.ReceiverId = e.ReceiverId) 
INNER JOIN Users u1 
ON (e.SenderId = u1.Id) 
INNER JOIN Users u2 
ON (e.ReceiverId = u2.Id) 
WHERE u.Id = @id;

Answer 3