SELECT b.DEPT_CODE, b.DEPT_NAME, a.ORDER_NO, TBL_CUST.CUST_CODE, TBL_CUST.CUST_NAME, a.ORDER_AMT
FROM TBL_ORDERS　as a 

INNER Join TBL_DEPT as b ON a.DEPT_CODE = b.DEPT_CODE

LEFT OUTER JOIN TBL_CUST as c on a.CUST_CODE =c.CUST_CODE

ORDER BY a.DEPT_CODE asc a.CUST_CODE