SELECT   lok.resource_type
        ,lok.resource_subtype
        ,DB_NAME(lok.resource_database_id)
        ,lok.resource_description
        ,lok.resource_associated_entity_id
        ,lok.resource_lock_partition
        ,lok.request_mode
        ,lok.request_type
        ,lok.request_status
        ,lok.request_owner_type
        ,lok.request_owner_id
        ,lok.lock_owner_address
        ,wat.waiting_task_address
        ,wat.session_id
        ,wat.exec_context_id
        ,wat.wait_duration_ms
        ,wat.wait_type
        ,wat.resource_address
        ,wat.blocking_task_address
        ,wat.blocking_session_id
        ,wat.blocking_exec_context_id
        ,wat.resource_description
FROM    sys.dm_tran_locks lok
JOIN    sys.dm_os_waiting_tasks wat
ON      lok.lock_owner_address = wat.resource_address

List of current sessions causing blocking

sql

SQL