Selecting all from tbl A that does not exist in tbl B

[Fredrik Dahlin]

Hello!

I have what I hope to be a simple question. I have two tables A and B. They both have one column "id". Lets say that A contains

id
====
1
2
3

And B contains

id
====
1
2
3
4

Now, I would like to make a query that will tell me which rows in B that does not have a match in A. In the above case, it would only be the row with '4'. Can anyone help me out?

Regards
/Fredrik