更新数据库未使用自定义初始化程序

Question

Please do not mistake this SO question as a duplicate:

I have the following config for a custom database initializer for code first entity framework:

<entityFramework>
  <contexts>
    <context type="MyApp.Context, MyApp">
      <databaseInitializer type="MyApp.CustomInitializer, MyApp" />
    </context>
  </contexts>
</entityFramework>

When I run the application all is well and the InitializeDatabase(Context context) method is called as expected.

However, when running the command Update-Database in the Package manager console it is not using my custom initializer.

Why does it work when running the app but not from the package manager console? Which initializer will it be using?

Answer 1

If you call Update-Database without specifying where is the ConfigurationType it is assumed that it is in the same assembly. An example :

Update-Database -ProjectName MyApp.Migrations -ConfigurationTypeName "MyApp.Migrations.MyMigrationConfiguration" -ConnectionString "Data Source=.\SQLEXPRESS;Database=myAppDb;Trusted_Connection=False;User ID=xx;Password=xxxxxx" -ConnectionProviderName "System.Data.SqlClient"

Answer 2

Unfortunately, Update-Database does not use a database initializer at all. It creates a DbMigrator to handle the update (which is also what the MigrateDatabaseToLatestVersion initializer uses), and either tries to find a DbMigrationsConfiguration class or uses one that you provide on the command line.

If you need to do some maintenance after a migration, you can use the Up() function in the migration itself. Or I suppose you could the Seed() function in your class that overrides DbMigrationsConfiguration (but by default, Seed() runs for every database initialization...however, there are ways to work around this.)

If you want to see it at work: https://entityframework.codeplex.com/SourceControl/latest#src/EntityFramework/Migrations/Design/ToolingFacade.cs