Having clause does not work

Question

Hi
I do following on one of our clients dbs:
select s.member_no,s.room_nights
from stay_records s, memberships m          
where s.member_no is not null
and s.member_no=m.membership_card_no
group by s.member_no,s.room_nights
having sum(s.room_nights) >= '2'
I basically want to find all members that have stayed two or more nights, the problem is that the query returns lots of one nighters as well. Have I made a mistake in my query?
I'm absolutely sure that the link between the tables are correct.
Apreciate your help.
/Robert

Answer 1

select s.member_no,sum(s.room_nights) room_nights
from stay_records s, memberships m
where s.member_no is not null
and s.member_no=m.membership_card_no
group by s.member_no
having sum(s.room_nights) >= 2ie. don't group by room_nights, and don't surround the 2 with single-quotes.