Get the deadlock Get the deadlock details

SELECT XEvent.query('(event/data/value/deadlock)[1]') AS DeadlockGraph
FROM ( SELECT XEvent.query('.') AS XEvent
       FROM ( SELECT CAST(target_data AS XML) AS TargetData
              FROM sys.dm_xe_session_targets st
                   JOIN sys.dm_xe_sessions s
                   ON s.address = st.event_session_address
              WHERE s.name = 'system_health'
                    AND st.target_name = 'ring_buffer'
              ) AS Data
              CROSS APPLY
                 TargetData.nodes
                    ('RingBufferTarget/event[@name="xml_deadlock_report"]')
              AS XEventData ( XEvent )
      ) AS src;