Maybe I should have added: it doesn't know what's in your database at runtime. It's not you'll be ad hoc modifying your DB. It's that your schema and your appl

Maybe I should have added: it doesn't know what's in your database at runtime. It's not you'll be ad hoc modifying your DB. It's that your schema and your application-side entities will change over time (continuously, during development, and somewhere between continuously and periodically in production, depending on how you release). Generally you won't be able to guarantee that they are updated in lock-step, or you won't want to pay the price to ensure that they always are.