sql查询备份或还原等操作的大概完成时间

--查询备份或还原等操作的大概完成时间
   select command
   ,percent_complete
   ,running_time=convert(varchar,((datediff(s,start_time,getdate()))/3600))+‘ hour, ‘
                +convert(varchar,((datediff(s,start_time,getdate()))%3600/60))+‘ min, ‘
                +convert(varchar,((datediff(s,start_time,getdate()))%60))+‘ sec‘
   ,est_time_to_go=convert(varchar,(estimated_completion_time/1000)/3600)+‘ hour, ‘
                  +convert(varchar,(estimated_completion_time/1000)%3600/60)+‘ min, ‘
                  +convert(varchar,(estimated_completion_time/1000)%60)+‘ sec‘
   ,start_time=convert(char(16),start_time,120)
   ,est_completion_time=convert(char(16),dateadd(second,estimated_completion_time/1000,getdate()),120)   
   ,s.text
   from sys.dm_exec_requests r
   cross apply sys.dm_exec_sql_text(r.sql_handle) s
   where r.command in (‘BACKUP DATABASE‘,‘RESTORE DATABASE‘,‘BACKUP LOG‘,‘RESTORE LOG‘,‘DbccFilesCompact‘,‘DbccSpaceReclaim‘)