select 
    dep.DEPT_CODE,
    DEPT_NAME,
    ORDER_NO,
    cus.CUST_CODE,
    CUST_NAME,
    ORDER_AMT
from tbl_orders as odr
inner join tbl_dept as dep
on dep.dept_code=odr.dept_code
left outer join tbl_cust as cus
on odr.cust_code=cus.cust_code
order by dep.dept_code,order_no;