SELECT login_name,  
       Count(0) user_count  
FROM   Sys.dm_exec_requests dr WITH(nolock)  
       RIGHT OUTER JOIN Sys.dm_exec_sessions ds WITH(nolock)  
                     ON dr.session_id = ds.session_id  
       RIGHT OUTER JOIN Sys.dm_exec_connections dc WITH(nolock)  
                     
 
ON ds.session_id = dc.session_id  
WHERE  ds.session_id > 50  
GROUP  BY login_name  
ORDER  BY user_count DESC 

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