select mm.pp as CODE, mm.CUST_NAME as NAME,
COUNT(DISTINCT mm.ORDER_DATE) as CNT
from
((select 
cu.CUST_CODE as pp,CUST_NAME
from CUSTOMER as cu)
as aa
join
(select 
ord.CUST_CODE as nn, ORDER_DATE
from ORDERS as ord
where ORDER_DATE BETWEEN '2023-07-01' AND '2023-07-31')
as bb
on
aa.pp = bb.nn
)
as mm
group by NAME
order by CNT desc, CODE