Tomasz,
> > This will not get you the same result as the above. It will get you
> > all rows from t+f where a record is present in f and has (or does not
> > have) a NULL value for f.id. While this type of query works in MS
> > Access, it will not work in SQL92/99-commpliant databases.
>
> filter_table does not contain null fields. It has only two states: it
> has row
> or it hasn't row coresponding to row in some_table.
>
> And now, which one is better?
You're not listening. I said that LEFT JOIN won't work. At all.
Please re-read the paragraph above, which explains why.
--
-Josh Berkus
Aglio Database Solutions
San Francisco