select X.DEPT_CODE, X.DEPT_NAME, Y.ORDER_NO, Z.CUST_CODE, Z.CUST_NAME, Y.ORDER_AMT
FROM TBL_ORDERS Y
inner join TBL_DEPT X
on X.DEPT_CODE = Y.DEPT_CODE
left outer join TBL_CUST Z
on Z.CUST_CODE = Y.CUST_CODE
order by X.DEPT_CODE, Y.ORDER_NO;