Delete records not included in a new import based on a unique ID?
I have attempted to search the forum for a solution to my question, but have not found one that appears to satisfy my need.
I have a db that has a unique ID number for each record. A new set of records needs to be imported to update the db, however, I only want to keep or update the records for those IDs in the import. All other ID numbers would be considered "outdated" and therefore could be deleted. Is there a way to do this on import? (If there is an ID that matches, keep the record; if there is a new ID in the import, add it; delete the rest.)
It seems like someone must have asked this before here, but I could not find a solution (or translation to solution) the way I was searching. Thanks for any assistance or a re-direct!