SELECT
DPT.DEPT_CODE,
DPT.DEPT_NAME,
OD.ORDER_NO,
CST.CUST_CODE,
CST.CUST_NAME,
OD.ORDER_AMT
FROM TBL_ORDERS AS OD
JOIN TBL_DEPT AS DPT
USING(DEPT_CODE)
LEFT JOIN TBL_CUST AS CST
USING(CUST_CODE)
ORDER BY 1,3;