.net - Modifying an Entity Framework Model at Run-Time

Question

This is purely a conceptual and design idea related to EF4.

The example/scenario is a large ERP or CRM type system where companies may need to add traditional "user defined fields" to capture additional data.

I know that the EF has some capabilities to push out the model to a database at run-time but the question really is can you use EF to modify a model and update the data store in real-time?

In other words, if I provide the user a mechanism to add a user defined column, associated data type and null requirements can that be done on the fly with EF and then remembered for all future sessions?

It's out there but I think you all will see what I'm getting at.

Brent

Answer 1

I've been asked this question a few times in the past. There is no obvious or easy way. It's possible that there is no way but we are developers and there's always a way! Do I know what that is? No. Can I dream up some ideas? ....Mmmm.. at runtime, the model is based on strongly typed classes from the metadataworkspace. You can create those on the fly. But then you need to modify the xml of the edmx file.There's LINQ to XML or xpath for that. Modifying the database schema... how does model first build dbs...it creates sql and then you execute it. You'd have to create sql (how? shrug) and the execute it (objectcontext.executestorecommand()). Feasible? Possible? I have no clue. Really the answer is no...there's nothing in VS or .NET 4 (EF APIs) to readily enable this as far as I know. Surely someone more clever and patient than I was spent (wasted??) a lot of time (trying to) outsmart EF to pull this off. Based, however, on your response t the suggestion re Jeremy's blog post, you're looking for something built in/handy. That is easier to answer with a "nope".

julie