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How can I get my database to seed using Entity Framework CodeFirst?

The database is created successfully (as are the tables) but is not seeded. I have spent several hours and read tons of articles but have not been able to get it. Any suggestions?

On a side note, is it possible to call the initializer without having a reference to my DatabaseContext in the client?

I have included all the relevant code I could think of. If anything else would be helpful, please let me know.

Things I've Tried:

  1. I deleted my connection string (since it defaults to sqlexpress anyways, just the name changed)
  2. I changed DropCreateDatabaseIfModelChanges to DropCreateDatabaseAlways, still the same.

Edit: The really weird thing is it worked once, but I have no idea how or why it broke again. I am assuming connection strings, but who knows.

DatabaseInitializer.cs

public class DatabaseInitializer : DropCreateDatabaseIfModelChanges<DatabaseContext>
{
  protected override void Seed(DatabaseContext context)
  {
    // Seeding data here
    context.SaveChanges();
  }
}

DatabaseContext.cs

public class DatabaseContext : DbContext
{
  protected override void OnModelCreating(DbModelBuilder mb)
  {
    // Random mapping code
  }

  public DbSet<Entity1> Entities1 { get; set; }
  public DbSet<Entity2> Entities2 { get; set; }

}

Global.asax.cs - Application_Start()

protected void Application_Start()
{
  Database.SetInitializer<DatabaseContext>(new DatabaseInitializer());
  AreaRegistration.RegisterAllAreas();
  RegisterGlobalFilters(GlobalFilters.Filters);
  RegisterRoutes(RouteTable.Routes);
}

Client web.config

<connectionStrings>
  <add name="DatabaseContext" connectionString="data source=.\SQLEXPRESS;Database=Database;Integrated Security=SSPI;" providerName="System.Data.SqlClient" />
</connectionStrings>

SOLUTION

For the sake of documentation, I am sharing my solution here. Navigating all the comments would be a pain anyways. In the end I had DatabaseInitializer and DatabaseContext in separate classes. I don't really understand while these tiny changes fixed it, but here it is.

DatabaseInitializer.cs

public class DatabaseInitializer : CreateDatabaseIfNotExists<DatabaseContext>
{
  protected override void Seed(DatabaseContext context)
  {
    // Seed code here
  }
}

DatabaseContext.cs

public class DatabaseContext : DbContext
{
  public DatabaseContext() : base("MyDatabase") { }

  protected override void OnModelCreating(DbModelBuilder mb)
  {
    // Code here
  }

  public DbSet<Entity> Entities { get; set; }
  // Other DbSets
}

Global.asax.cs - Application_Start()

protected void Application_Start()
{
  Database.SetInitializer(new DatabaseInitializer());
  AreaRegistration.RegisterAllAreas();
  RegisterGlobalFilters(GlobalFilters.Filters);
  RegisterRoutes(RouteTable.Routes);
}
like image 575
Alec Avatar asked Jun 10 '11 21:06

Alec


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Database. EnsureCreated() to create a new database containing the seed data, for example for a test database or when using the in-memory provider or any non-relational database. Note that if the database already exists, EnsureCreated() will neither update the schema nor seed data in the database.

Which method can be used to seed initial data in database using Entity Framework Core?

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6 Answers

This is what my DbContext classes all look like and they seed just fine:

public class MyDbContext : DbContext
{
    public DbSet<MyClass> MyClasses { get; set; }

    protected override void OnModelCreating (DbModelBuilder modelBuilder)
    {
        base.OnModelCreating (modelBuilder);
        modelBuilder.Conventions.Remove<System.Data.Entity.ModelConfiguration.Conventions.PluralizingTableNameConvention> ();

        // Add any configuration or mapping stuff here
    }

    public void Seed (MyDbContext Context)
    {
        #if DEBUG
        // Create my debug (testing) objects here
        var TestMyClass = new MyClass () { ... };
        Context.MyClasses.Add (TestMyClass);
        #endif

        // Normal seeding goes here

        Context.SaveChanges ();
    }

    public class DropCreateIfChangeInitializer : DropCreateDatabaseIfModelChanges<MyDbContext>
    {
        protected override void Seed (MyDbContext context)
        {
            context.Seed (context);

            base.Seed (context);
        }
    }

    public class CreateInitializer : CreateDatabaseIfNotExists<MyDbContext>
    {
        protected override void Seed (MyDbContext context)
        {
            context.Seed (context);

            base.Seed (context);
        }
    }

    static MyDbContext ()
    {
        #if DEBUG
        Database.SetInitializer<MyDbContext> (new DropCreateIfChangeInitializer ());
        #else
        Database.SetInitializer<MyDbContext> (new CreateInitializer ());
        #endif
    }
}

I have used this pattern a few times and it has worked out very well for me.

like image 167
Jim D'Angelo Avatar answered Sep 30 '22 21:09

Jim D'Angelo


My Seed method was not invoked even with proper call to Database.SetInitializer in Application_Start... The reason for it was really simple: initializer may not be invoked at all if you don't yet have any code that actually uses database context.

like image 26
user1068352 Avatar answered Sep 30 '22 23:09

user1068352


This is my sad little tale.

First, lessons learned:

  1. The seed method won't be called until the context is used.
  2. The Global.asax.cs won't hit a breakpoint on first run bc it runs before the debugger is attached. To hit a breakpoint on Global.asax.cs, you have can add some white space to Web.config and hit a page; then it will get hit.
  3. If there are VS connections to the db, the seeding won't happen. The app will throw an error.

So, to avoid the sadness:

  • Disconnect your VS connection.
  • Switch the base class DropCreateDatabaseAlways for one go.
  • Hit a page that uses the context.

Now, the sadness:

  1. I had my custom Initializer class in my Global.asax.cs file. I had a break point on my Initializer Seed method; I started the application and the method never got hit. :(
  2. I point a break point in my Database.SetInitializer call in Application_Start. That never got hit. :(
  3. I realized that I had no db schema changes, so then I changed DropCreateDatabaseIfModelChanges to DropCreateDatabaseAlways. Still, nothing. :(
  4. I finally went to a page that uses the context, and it worked. :/
like image 38
Davious Avatar answered Sep 30 '22 23:09

Davious


You can call update-database to manually run the seed method inside the Configuration class. This requires enable-migrations to be on as well.

PM> update-database
Specify the '-Verbose' flag to view the SQL statements being applied to the target database.
No pending code-based migrations.
Running Seed method.

internal sealed class Configuration : DbMigrationsConfiguration<ProjectManager.Data.Database.ProjectDb>
{
    public Configuration()
    {
        AutomaticMigrationsEnabled = false;
    }

    protected override void Seed(ProjectManager.Data.Database.ProjectDb context)
    {
        context.Status.AddOrUpdate(
            new Status() { Id = 1, Text = "New" },
            new Status() { Id = 2, Text = "Working" },
            new Status() { Id = 3, Text = "Completed" },
            new Status() { Id = 4, Text = "Skipped" }
        );
    }
}
like image 42
Despertar Avatar answered Sep 30 '22 23:09

Despertar


The following change in the Global.asax file worked for me:

Old Code:

    protected void Application_Start()
    {
        Database.SetInitializer<mycontextclassname>(new DropCreateDatabaseAlways<mycontextclassname>());             
       ...
    }

New Code:

    protected void Application_Start()
    {
        Database.SetInitializer<mycontextclassname>(new DropCreateDatabaseAlways<mycontextclassname>()); 
        Database.SetInitializer(new Initializer()); 
        ...
    }
like image 34
Steven Burton Avatar answered Sep 30 '22 23:09

Steven Burton


I too have had difficulty getting Seed() to be invoked. And I do appreciate all the helpful suggestions above and have had some luck using DropCreateDatabaseAlways ... but not ALWAYS!!

Most recently, I added the following line of code in the the constructor of my Repository to good effect:

    public CatalogRepository()
    {
        _formCatalog.FormDescriptors.GetType();

    }

It was sufficient to trigger the Seed() getting invoked. If you've tried everything above this answer and still no luck, give it a try. Good luck this was really a time consuming experience.

like image 21
Joe Avatar answered Sep 30 '22 23:09

Joe