select
    td.DEPT_CODE
    , td.DEPT_NAME
    , tor.ORDER_NO
    , tc.CUST_CODE
    , tc.CUST_NAME
    , tor.ORDER_AMT 
from
    TBL_DEPT as td
    
    inner join  TBL_ORDERS as tor
        on td.DEPT_CODE = tor.DEPT_CODE
    
    left outer join TBL_CUST as tc
        on tc.CUST_CODE = tor.CUST_CODE 
order by
    tor.DEPT_CODE asc
  , tor.ORDER_NO asc;