The model backing the ‘‘ context has changed since the database was created. Consider using Code First Migrations

DB Context has changed

I was working with an example in Entity Framework 5 and ran across this commonly seen issue that DB context has changed, especially after changing my Books model.

The model backing the 'BooksDbContext' context has changed since the database was created. Consider using Code First Migrations

DB context has changed headache

This really mean that my database was unaware that my model was changed. My Books database had to be modified appropriately. Visual Studio offers a package manager that allows us to easily update the database based on the model. This method is the Code First method as opposed to Database First method; I, personally, like the Database First method.

The fix to DB context changing

Open Tools — Library Package Manager — Package Manager Console
Type EnableMigrations -ContextTypeName ExampleMVC.Models.BooksDbContext
Then, do EnableMigrations -EnableAutomaticMigrations
Type Add-Migration ExampleMVC.Models.BooksDbContext
Finally, use Update-Database -Verbose

Now run your application and the error should be gone.