asp.net - How and where to call Database.EnsureCreated and Database.Migrate?

Question

I have a ASP.NET MVC 6 application, and i need to call the Database.EnsureCreated and Database.Migrate methods.

But where should I call them?

Answer 1

I think this is an important question and should be well answered!

What is Database.EnsureCreated?

context.Database.EnsureCreated() is new EF core method which ensures that the database for the context exists. If it exists, no action is taken. If it does not exist then the database and all its schema are created and also it ensures it is compatible with the model for this context.

Note: This method does not use migrations to create the database. In addition, the database that is created cannot later be updated using migrations. If you are targeting a relational database and using migrations, you can use the DbContext.Database.Migrate() method to ensure the database is created and all migrations are applied.

How did we do that with EF 6?

context.Database.EnsureCreated() is equivalent to the below listed approaches of EF 6:

1. Package Manager Console:

   Enable-Migrations -EnableAutomaticMigrations. Add-Migration/Update-Database.

2. From code:

   Database.SetInitializer CreateDatabaseIfNotExists

or

With DbMigrationsConfiguration and set AutomaticMigrationsEnabled = true;

What is Database.Migrate?

Applies any pending migrations for the context to the database. Will create the database if it does not already exist.

How did we do that with EF 6?

context.Database.Migrate() is equivalent to the below listed approaches of EF 6:

1. Package Manager Console:

   Update-Database -TargetMigration

2. With a custom DbMigrationsConfiguration:

   AutomaticMigrationsEnabled = false; or with DbMigrator.

Conclusion:

If you are using migrations there is context.Database.Migrate(). If you don't want migrations and just want a quick database (usually for testing) then use context.Database.EnsureCreated()/EnsureDeleted().