We need to migrate data from a ms access db to sql server. As ms access preserves the records in the order in which they were actually inserted, and the application logic depends on it (the last() function in ms access) , we need to maintain the same order in the sql server db.

So, we thought of having an identity col which can be used for replicating the last() functionality in ms access.

The problem is, while migrating the existing data, the id column should be the actual position of that record in the original ms access db.