Use an outer join. Include All records in the table that should have no
missing records and include the matching records from the table you want to
check for missing (unmatched) records in. Include at least one field from
the unmatched table. For every record in the first table that doesn't have a
match in the second table you will get a Null value in the field from the
second table. Set your criteria on this field to Is Null. You will now only
get records from the first table that don't have records in the second.
