Help needed with a Join query

[La_Parka]

My site's users take tests, and their responses are recorded in a "response" table. Here are the relevant tables:

User
userID

Test
testID

Response
responseID
testID
userID

I'm trying to create a query that will return all of the DB's testIDs, and indicate if a given userID has taken them. For tests not taken by a user, NULLs will be returned.

Let's say that the DB contains six tests, numbered 1-6. User #4 has taken every test, except for numbers 4 and 5, so there would be responseIDs linking userID #4 to those testIDs. Is there a simple way to get what's depicted in the attached image, without having to turn to temporary tables or other complex solutions?

[bogu]

I think this is what u are looking for?

SELECT u.userID, t.testID FROM Response r
LEFT JOIN Test t USING(testID)
LEFT JOIN User u ON r.userID = u.userID