sql add sort by :  Actually i try to sort my sql but it's not sorting 

where i need to add SORT BY TSTATUS

 $sql="
	        (
	          SELECT
	            tt.tstatus,
	            tt.ticketnbr,
	            tt.col1,
	            tt.col2,
	            NULL as col3,
	            tt.col4,
	            tt.col5,
	            tt.col6,
	            tt.col7,
	            tt.col8,
	            'cmg' as tickettype,
              CASE WHEN cl.parentid IS NOT NULL THEN 1 ELSE 0 END as has_log
	          FROM
              aradmin.cmg_troubleticket tt
	            LEFT JOIN
	              ARADMIN.TT_CUSTOMERLOGENTRY cl 
            ON ( tt.ticketnbr=cl.parentid AND cl.schema='AR:TroubleTicket' AND cl.status=0 )
        WHERE
          ( tt.TSTATUS < 9 )
          {$customer_list} 
          	            
      ) UNION (
        SELECT
          tt.tstatus,
          tt.ticketnbr,
          tt.col1,
          tt.col2,
          tt.col3,
	            tt.col4,
	            tt.col5,
	            tt.col6,
	            tt.col7,
	            tt.col8,
	            'ar' as tickettype,
	            CASE WHEN cl.parentid IS NOT NULL THEN 1 ELSE 0 END as has_log
	          FROM
	            aradmin.ar_troubleticket tt
	            LEFT JOIN
	              ARADMIN.TT_CUSTOMERLOGENTRY cl 
	              ON ( tt.ticketnbr=cl.parentid AND cl.schema='AR:TroubleTicket' AND cl.status=0 )
	          WHERE
	            ( tt.TSTATUS < 10 )
	            {$customer_list} 
          )
	      ";

