I think the main reason for this is that, like every database, DVD Profiler needs some unique key for every record in the database. For DVD Profiler this is the UPC field. At some point, it was decided to also support disks without UPC and there the Disk ID could be used as the key. Personally, I see this as a dirty hack though... It would indeed make more sense to have them in separate fields and maybe use the two fields combined as the primary key. This would immediately solve the problem with two different DVDs having the same UPC. The primary key would still be different because the Disk ID is different. The main disadvantage however is that then everybody would have to use the Disk ID as well which is difficult because: a) not everyone would have a DVD-ROM in their PC and/or willing to everytime enter the disk in the drive. b) there would have to be a convention with multi-disk sets on what disk to use. Edit: now I realize that in fact it is UPC/DiskId + Locality that currently is the primary key. In fact, I have a much better idea now...and will start a new thread on that . |