Last week as part of a migration from ASP.NET 5 beta 4 to beta 5 I deleted all the entity framework migrations for a project. This post is going to walk through the process deleting the existing database, creating new migrations and applying the new migrations.
The first step is to delete the existing database associated with the project. To do this from within Visual Studio 2015 open the SQL Server Object Explorer. Click on the Add SQL Server button (second button).
The add button launches the Connect to Server dialog. If using the default setup with SQL Server Express the settings below should work. After all the relevant information has been entered click connect.
Right click on the database for the application and click delete.
Another option would be to change the database name in the connection string which would also trigger entity framework to create a new database.
The next step is to add migrations for each DbContext in your project. The following two commands, run from the command prompt, will add migrations for the two contexts associated with my application.
dnx . ef migration add ApplicationInit --context ApplicationDbContext dnx . ef migration add ContactsInit --context ContactsDbContext
The following is a repeat, but it is important part of the setup since in it is how this application applies migrations. The constructors of the DbContext classes apply migrations as demonstrated in the following code.
public class ContactsDbContext : DbContext
{
private static bool _created;
public DbSet<Contact> Contacts { get; set; }
public ContactsDbContext()
{
if (!_created)
{
Database.AsRelational().ApplyMigrations();
_created = true;
}
}
}
After the first run of the application a new database will be created and you will be ready to go with a fresh database.