SELECT
    td.DEPT_CODE,
    DEPT_NAME,
    ORDER_NO,
    tc.CUST_CODE,
    CUST_NAME,
    ORDER_AMT
FROM
    TBL_ORDERS as tor
INNER JOIN
    TBL_DEPT as td
ON  
    tor.DEPT_CODE = td.DEPT_CODE
LEFT JOIN
    TBL_CUST as tc
ON
    tor.CUST_CODE = tc.CUST_CODE
ORDER BY
    tor.DEPT_CODE ,tor.ORDER_NO ASC;