need a mysql guru

[Saeven]

I have two tables that each contain a similar key called domain.

I would like to select all domains from table 1 that are not included in table 2.

In algebraic notation:

t1 := project domain(table1);
t2 := project domain(table2);

project domain( t1 difference t2);

How is this done in mysql?

Looking forward to your replies.
Alex

[Saeven]

NM

Got it.

SELECT domain
FROM table1
LEFT JOIN table2 ON table1.domain = table2.domain
WHERE table2.domain IS NULL

You can get the alternate result with IS NOT NULL