How to execute seed step using migration.exe on existing database? - entity-framework

Question

I have someone else's ASP.NET application that uses code-first EF and comes with the code for database migration and seed. I usually run migration.exe before the new version of the app gets installed and it worked well as long as I let EF do everything starting from creating a brand new database. Now I have to make it work against an existing and EMPTY database. When I run migration.exe it doesn't return any errors and perform all the required migration steps but it not longer runs seed step (it probably assumes it's not needed since the database already exists). How do I force running seed step in this case?

Answer 1

There are steps you need to ensure are set for your database initialization to achieve what you want:
CreateDatabaseIfNotExists: This is default initializer. As the name suggests, it will create the database if none exists as per the configuration. However, if you change the model class and then run the application with this initializer, then it will throw an exception.
DropCreateDatabaseIfModelChanges: This initializer drops an existing database and creates a new database, if your model classes (entity classes) have been changed. So you don't have to worry about maintaining your database schema, when your model classes change.
DropCreateDatabaseAlways: As the name suggests, this initializer drops an existing database every time you run the application, irrespective of whether your model classes have changed or not. This will be useful, when you want fresh database, every time you run the application, like while you are developing the application.
Custom DB Initializer: You can also create your own custom initializer, if any of the above doesn't satisfy your requirements or you want to do some other process that initializes the database using the above initializer.
The best help guide I followed with getting started on understanding Code first was written here and references the part you are referring to:
http://www.entityframeworktutorial.net/code-first/database-initialization-strategy-in-code-first.aspx
The important thing though is to know that you may want different things for different environments too and may wish to get into understanding how to do different deployments for different environments.
An example of a custom one would be like this:
public class EasyContext : DbContext
{
public EasyContext() : base("name=EasyEntity")
{
Database.SetInitializer<EasyContext>(new EasyInitializer());
}
public DbSet<Person> Person { get; set; }
}
You should be setting a breakpoint to make sure it is being caught or else you can force a new configuration to fire as well.