I have a funny effect using migration (EF 5.0) and code-first:
I created some models with GUID primary keys. (BTW: It is important for me, that SQL Server uses NEWSEQUENTIALID(), which seems to be the default value in the current version)
At some point I activated migrations. I added some code to the initial migration, this is mostly .Index() as needed.
When I delete the database and call update-database, I get the following error:
Unable to update database to match the current model because there are pending changes and automatic migration is disabled. Either write the pending model changes to a code-based migration or enable automatic migration. Set DbMigrationsConfiguration.AutomaticMigrationsEnabled to true to enable automatic migration. You can use the Add-Migration command to write the pending model changes to a code-based migration.
I tried AutomaticMigrationsEnabled = true, which worked without changing or adding anything!
But since I don't want AutomaticMigrationsEnabled, I also tried deleting the database again, called update-database and then add-migration. I ended up with an additional migration that seems not to change anything (see below). I also tried adding these lines to the bottom of the initial migration - but this does not change anything.
One of the models:
[Table(Speaker.TABLENAME)]
public class Speaker : BaseModel
{
public const String TABLENAME = "Speaker";
[Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public Guid Id { get; set; }
[Required]
[MaxLength(50, ErrorMessage = "Name must be 50 characters or less")]
public string Name { get; set; }
}
The initial migration code:
public partial class InitialCreate : DbMigration
{
public override void Up()
{
// [...]
CreateTable(
"dbo.Speaker",
c => new
{
Id = c.Guid(nullable: false, identity: true),
Name = c.String(nullable: false, maxLength: 50),
})
.PrimaryKey(t => t.Id)
.Index(t => t.Name, true, false); // added manually: unique Name
// [...]
}
}
internal sealed class Configuration : DbMigrationsConfiguration<MyProject.Repositories.DBContext>
{
public Configuration()
{
AutomaticMigrationsEnabled = false;
}
protected override void Seed(MyProject.Repositories.DBContext context)
{
// ...
}
}
Below is the code created by add-migration: It does not seem to do anything new - maybe I am missing something?
public partial class UnneccessaryMigration : DbMigration
{
public override void Up()
{
// isn't this the exact same code from InitialMigrations?
AlterColumn("dbo.Speaker", "Id", c => c.Guid(nullable: false, identity: true));
// ...
}
public override void Down()
{
//...
AlterColumn("dbo.Speaker", "Id", c => c.Guid(nullable: false));
}
}
So I am curious: What did I do to disorientate migrations? And what can I do to get it working with just one initial migration?
Solution: The following workaround did it for me:
- I deleted the database and all migrations as decribed here: https://stackoverflow.com/a/11679386/3168401
- Executed Enable-Migrations + Add-Migration Initial
- Merged my handmade .Index() changes into the file. Now Update-Database works again - also repeatedly, when deleting the database.
