在实体框架中更新视图的问题

Question

For some reasons we need to update Views inside the Entity Framework . So we followed this solution on another question and it worked like a charm!

BUT here is the problem:
if we update our model (for some new fields or tables/views) the complete Mappings are destroyed and after updating we get the Warning

Error 11007: Entity type 'UpdateView1' is not mapped.

After this it's not even possible to load the entities because all Mappings are lost.
So how to design the views to be able to post updates using the Views AND to be able to update the edmx file?

Answer 1

MS is dropping support for EDMX files going forward in Entity Framework - in part due to the difficulty of keeping the database, EDMX, and POCOs all sync'd, as you are experiencing. (Anyone can edit any of the 3, then changes are lost when a sync is done).

So they recommend using the Code First approach. Code First is a bit of a misnomer and causes some confusion.

Code First doesn't mean you have to start with code.
You can start with the database and then write your POCOs to match it (as in your case). Doing so allows you to preserve all your mappings and such because you just adjust your code to match the structure already present in your database.

Another misconception is that you have to use migrations . You do not. You are welcome to not enable migrations and manually edit both the database schema and POCOs as long as you ensure they remain in sync.