When you add DFP to a page, there are several data bindings created including the file name of the uploaded file. YOu can see a list of the available data bindings by going to the DFP help page:
Go to Features, then Upload wizard and scroll down.
To use a databinding, you can drag it out onto your page if you simply want to write it out, or you can use that value to update your database. If you're using DataAssist, then you can use access the data bindings to set the selected data binding as the value to insert/update a table.