SELECT
D.DEPT_CODE,
DEPT_NAME,
ORDER_NO,
C.CUST_CODE,
CUST_NAME,
ORDER_AMT
FROM TBL_ORDERS AS O
LEFT JOIN TBL_CUST AS C
ON C.CUST_CODE = O.CUST_CODE
INNER JOIN TBL_DEPT AS D
ON D.DEPT_CODE = O.DEPT_CODE
ORDER BY D.DEPT_CODE, O.ORDER_NO