SELECT
    DEPT.DEPT_CODE,
    DEPT_NAME,
    ORDER_NO,
    CUST.CUST_CODE,
    CUST_NAME,
    ORDER_AMT
FROM
    TBL_ORDERS AS ORDERS
INNER JOIN
    TBL_DEPT AS DEPT
ON  DEPT.DEPT_CODE = ORDERS.DEPT_CODE
LEFT JOIN
    TBL_CUST AS CUST
ON  CUST.CUST_CODE = ORDERS.CUST_CODE
ORDER BY
    ORDERS.DEPT_CODE,
    ORDER_NO