Cool - is it an ascending number?
The reason I ask: one way to do this would be to query your existing data, get max(id) and then get the new data by selecting from it where id > maxid.
By the way, what happens if changes to existing data occur - don't you want to update that too?
If you haven't even tried to resolve your issue, please don't expect the hard-working volunteers here to waste their time providing links to answers which you could easily have found yourself.