select 
     td.dept_code
    ,td.dept_name
    ,tor.order_no
    ,tc.cust_code
    ,tc.cust_name
    ,tor.order_amt
from tbl_orders as tor
inner join tbl_dept as td
on tor.dept_code = td.dept_code
left outer join tbl_cust as tc
on tor.cust_code = tc.cust_code
order by td.dept_code,tor.order_no