SELECT
    TBL_ORDERS.DEPT_CODE
    , TBL_DEPT.DEPT_NAME
    , TBL_ORDERS.ORDER_NO
    , TBL_ORDERS.CUST_CODE
    , TBL_CUST.CUST_NAME
    , TBL_ORDERS.ORDER_AMT
FROM TBL_ORDERS
INNER JOIN TBL_DEPT ON TBL_ORDERS.DEPT_CODE = TBL_DEPT.DEPT_CODE
LEFT JOIN TBL_CUST ON TBL_ORDERS.CUST_CODE = TBL_CUST.CUST_CODE;