select dept.DEPT_CODE
,dept.DEPT_NAME
,orders.ORDER_NO
,cust.CUST_CODE
,cust.CUST_NAME
,orders.ORDER_AMT
from TBL_ORDERS as orders
inner join TBL_DEPT as dept
on orders.DEPT_CODE = dept.DEPT_CODE
left join TBL_CUST as cust
on orders.CUST_CODE = cust.CUST_CODE
order by dept.DEPT_CODE, orders.ORDER_NO