It most cases it is preferential to store only the files name in the database.
If you wish to store the full url, you will need to append it to the server File Name binding in the insert record behavior.
When you bind to the Server File name in the insert record behavior, it will add code similar to:
<?php echo $WA_DFP_UploadStatus["WA_UploadResult1"]["serverFileName"]; ?>
you can add the full path in front of that to force it to tore the full URL:
http;//www.mydomian.com/images/<?php echo $WA_DFP_UploadStatus["WA_UploadResult1"]["serverFileName"]; ?>