The DB's responsible for maintaining the integrity of data in it, unless there's some very good reason you can't let it do that. It's faster and better at it th

The DB's responsible for maintaining the integrity of data in it, unless there's some very good reason you can't let it do that. It's faster and better at it than your application, 99% of the time, and it can keep doing that even when/if a second application starts using the same database, or when being used from a SQL prompt, or whatever.