OK, if you are going to have one table, and do an Append Query, you will need to do the following:
1. Add a new field to your table and call it DateAdded.
2. Update the DateAdded record for the existing records in your table. You can do this with an Update Query (or manually).
If using an Update Query, just use Criteria to select which records you want to update with what date (if using a date other than today, just enter that date in the DateAdded calculated field in your query).
3. If the new file you want to import contains both old and new records, and you only want to import the new records (since the old ones are already in your table), first import your records into a temporary table, then create an Unmatched Query between your temporary table and final table, so it only returns the new records you want to import (there is an Unmatched Query Wizard that will walk you through how to do that).
4. Add the DateAdded calculated field to the Unmatched Query and change it to an Append Query and run it to populate the new records.
One final note regarding your temporary table. You can either create a new one each time, or just clear the records out each time before importing your new file. You can even create a Macro to clean out those records with a click of the button. You would just use the RunSQL command with this line of code:
Code:
DELETE [TemporaryTableName].* FROM [TemporaryTableName];