select UserId,UserName, from ch_userregistration

 select  ReceiverId, COUNT(Message) from ch_singleconversation WHERE
 SenderId = '1002' AND MsgStatus='Y' GROUP BY ReceiverId

UserId  UserNeme`
-----------------
1001    Mohan
1002    Raj
1003    Mahesh
1004    rahul

ReceiverId    Count
---------------------------
 1002           8
 1004           4

UserId   UserName   Count
----------------------------
1001    Mohan        0
1002    Raj          8
1003    Mahesh       0
1004    rahul        4