Building .Net application entities after deployment

I am working on a product in which some business entities are defined after deployment based on inputs from the site administrator. The application then prepares a schema and creates sql objects (primarily tables) using the SQL Management Objects (SMO).

I now need to represent these entities in my application with following things in mind:

• When the site administrator changes the entities (only extensibility allowed ... no deletes, drops) the entities should be rebuilt. This happens in 'admin mode' when no user connections are allowed.

• On schema upgrades, the references to the attributes already established should not be disturbed. For eg., Employee.Firstname should still be accessible as开发者_运维百科 earlier ... positioning of the attributes should have no bearing.

Any suggestions on approach / tools? I've been looking at some code generation tools but not satisfied yet.