I have on my clipboard the identical query posted by deroby (I hope I'm pronouncing that correctly.) LEFT OUTER JOIN ... WHERE <somefield> IS NULL is a good step in learning how to solve these types I queries. Although shouldn't that step be followed by learning about WHERE NOT EXISTS?

To answer the Patrick's question "What am I missing?", you are missing the opportunity to show others how to properly use WHERE NOT EXISTS!

If the article ended with deroby's post, It would be a 5 star article. It has been my experience that WHERE NOT EXISTS always meets or beats a LEFT OUTER JOIN ... WHERE <somefield> IS NULL query.

Patrick, I do really like your test data generation queries. I learn something new everyday.