OK. I created a simple example of three tables named Table1, Table2, and Table3, each with field name "NB".
And I want to return all NB values from Table1 where the NB value is not found in either Table2 or Table3.
The query would look like this:
Code:
SELECT Table1.NB
FROM (Table1 LEFT JOIN Table2 ON Table1.NB = Table2.NB) LEFT JOIN Table3 ON Table1.NB = Table3.NB
WHERE (((Table2.NB) Is Null) AND ((Table3.NB) Is Null));
Basically, you get this by creating an Unmatched Query from Table1 to Table2 (using the Unmatched Query Wizard), and then edit the query, adding Table3, and creating the same join from Table1 to Table3 and adding the same criteria.