1. A method for updating a database, which comprises the steps of: determining whether a vehicle is in an on-road position based on information provided by an in-vehicle navigation system; generating a geographically coded image by using a vehicle-mounted camera, if the vehicle is not in an on-road position according to the information provided by the in-vehicle navigation system; and analyzing the geographically coded image generated by the vehicle-mounted camera in order to determine whether a geographic database requires updating.