SELECT D.DEPT_CODE
    ,DEPT_NAME
    ,ORDER_NO
    ,C.CUST_CODE
    ,CUST_NAME
    ,ORDER_AMT
FROM TBL_DEPT D
JOIN TBL_ORDERS O
ON (D.DEPT_CODE = O.DEPT_CODE)

LEFT OUTER JOIN TBL_CUST C
ON (O.CUST_CODE = C.CUST_CODE)

ORDER BY D.DEPT_CODE
AND ORDER_NO;