Howdy.

Quick question: How do I select data that is present in one table, but not in another?

simple example:

I've got a list of all my people in my phonebook. Another table has a list of the people who I owe money to.

If I want to do a query on people I can feel free to visit (IE, those in the phonebook, but who I don't owe money too), how would I do this?

Edit: I probably should mention that I'm using PostgreSQL.

Use a left join, and test for NULL values in the foreign key of the table of people you owe money to.

-PatP

Thanks.

Just solved it with a NOT IN command.

<-- Newb. :/

Just FYI, but NOT IN is "expensive" compared to NOT EXISTS. The LEFT OUTER JOIN solution is normally the "cheapest" solution.

-PatP