Entity Framework model change error

Question

I am getting the error

"The model backing the 'DataContext' context has changed since the database was created. Consider using Code First Migrations to update the database".

I am using Entity Framework and have changed my model after declaring DataContext. How can I fix this error?

Answer 1

If you delete the __MigrationHistory table in SQL Server it should fix it.

Answer 2

1. If you already deployed your application or you don't want remove data from database you must read about Code First Migrations. Here you have a link: http://msdn.microsoft.com/en-us/library/hh770484(v=vs.103).aspx

2. If you can delete database just do it. EF will create new database that match your model.

3. You can also disable creating/updating database structure by invoking the following code:

   Database.SetInitializer<MyDbContext>(null);
   

Answer 3

I used database first to create a project after I had changed my database context and solved my problem:

Database.SetInitializer<Models.YourDbContext>(null);

Don't forget to handle the DbUpdateException