query help

[jbyron]

I have 2 tables for the potential booking of conferences.

restricted(uid, conf_id)
conferences(conf_id, subject, others...)

restricted lists all the users who cannot attend certain conferences.

How do I get a list of all the possible conferences, with anything in restricted excluded from the list?

So far I have:

SELECT * FROM conferences, restricted WHERE restricted.uid='bloggs' AND restricted.conf_id=conferences.conf_id AND conferences.subkect='topic';

But this doesn't work. I was thinking of a left join but kept getting NULL values.

Can anybody help?

Thanks