[jerf]

DRY is "Don't Repeat Yourself", not "Don't Repeat Ever". If your ORM fully correctly derives everything it needs from your database schema, that doesn't count as a repeat. If your ORM needs a couple of hints, but those hints are indeed extra information that your DB can't have ("this isn't just a string, it's an IP address") that doesn't count as a repeat. If you personally typed your schema into a database creation script and then you personally also typed the same schema into your ORM specification, only then are you violating DRY.

Code generation is a powerful DRY tool, not something it suggests avoiding!

I say that independent from the question of whether you should be using an ORM at all. If you are going to use it, either your ORM should come out of the DB or be responsible for creating the DB, either is fine, as long as you're not saying the same thing twice.

[steveklabnik]

> DRY is "Don't Repeat Yourself", not "Don't Repeat Ever".

It's actually "Every piece of knowledge must have a single, unambiguous, authoritative representation within a system."

(this advances your point even further)

[jl6]

And makes clear that DRY is just a handy catchphrase for the design principle of normalization.