You need to use Data Assist in order to store the uploaded file name.
The File Upload of Digital File Pro creates a new binding group in the bindings panel named WA Uploaded Files (File Field Name) where "File Field Name" is the name of the file field in your form. This binding group contains a Server File Name binding.
you need to use this server file name binding in the upload to store the uploaded file name to the database.
the Dreamweaver update server behavior is limited in that it only allows you to use form bindings. Data Assist gives you the ability to select from any binding listed in the bindings panel for your dynamic data.