I have a database where if a customer has more than one record, if the customers "id" number is input into a field called "primary id", the database will run an event procedure that populates an outcome status that prevents an advisor from marketing the customer twice. I am looking to update the field called "primary id" automatically when a customers telephone number is duplicated by the database either when inputting or by running a query. This should automatically be populated by the first id number that matches the telephone number in the "id" field.

Any clues?