i think it will give a "not a group function" error
it gave me an error while trying this query using grup by after using joins
select cust.cust_id,cust.cust_name,rec.order_date,pay.inv oice_date from customers cust,
recievers rec,payers pay where
cust.cust_id=rec.cust_id and cust.cust_id=pay.cust_id
(round(sysdate-pay.invoice_date)<365)) group by
It seems that you spread the same question through several threads here ... Well, you obviously didn't follow your own scenario, nor correct SQL syntax. In the last query provided, include ALL columns into the GROUP BY to avoid an error message. However, as you don't use any aggregate function in the SELECT statement, GROUP BY will probably give the same result as if you didn't use it at all.
[EDIT] Sorry, I didn't notice that there were different posters in posts #1 and #3!