// App.config file setup example
<contexts>
      <context type="_01Data.Model.TodoContext, 01Data">
        <databaseInitializer type="_01Data.Test.TestDataInitializer, 01Data.Test" />
      </context>
    </contexts>

// create class
public class TestDataInitializer : DropCreateDatabaseAlways<TodoContext>
    {
        protected override void Seed(TodoContext context)
        {
            context.Severities.AddOrUpdate(s => s.Title, new Severity { Title = "Baromi Fontos" });
            context.Severities.AddOrUpdate(s => s.Title, new Severity { Title = "Kit erdekel" });

            base.Seed(context);
        }
    }

// create connection strings in App.config 
<connectionStrings>
    <add name="DefaultConnection" 
         connectionString="Server=.\SQLExpress;Database=TodoDbDev;Trusted_Connection=True;" 
         providerName="System.Data.SqlClient"/>
  </connectionStrings>