Subquery not returning results

I have a simple subquery:

select ckt_id, charges
from table A
where ckt_id not in (select distinct ckt_id from B) and charges > 0

I know of at least one record in A whose ckt_id is not present in table B and charges > 0 which is not being returned.

Table A has about 15000 records and B has about 50000 records.

What am I missing here?

Thanks in advance,
ZSashi Received on Wed Apr 08 2009 - 10:05:53 CDT