SQL Query Fails to return correct result

[JimReiley]

I'm trying to see if any record in AdHeader DOES NOT have a record in AdTextNew with the following sql statement.

SELECT * FROM AdHeader
where not exists
(select adnumber, entryyear from adtextnew)

It doesn't return any records from adheader which it should.

Any idea why it doesn't?

 

[TomKane]

What is the common key between the two tables?