Entity Framework WebAPI Model UpSerts - entity-framework

Question

I'm having problems with duplicate data during migration with Code First.
A new foreign key record is duplicated each time the migration creates the master record.
The schemas in the database are being created correctly. Namely the Primary Keys and Foreign Key values (the latter being automatically generated)
Can someone please advise thanks about how I detach the foreign key record during migration to prevent it recreating the record or any configuration I need to implement? I've tried updating the state of the foreign key obects before inserting master data. to both modified and detached.
For example I see multi records for the same priority where there should only be 3.
I'm using Entity Framework 6.0.
public class VeloPointDbConfiguration : DbMigrationsConfiguration<VeloPointDbContext>
{
public VeloPointDbConfiguration()
{
AutomaticMigrationsEnabled = true;
AutomaticMigrationDataLossAllowed = true;
}
protected override void Seed(VeloPointDbContext context)
{
context.TaskPriorities.AddOrUpdate(EventTaskPriority.Migrations.All());
context.TaskStatuses.AddOrUpdate(TaskStatus.Migrations.All());
EventOrganiserTask.Migrations.All().Select(x => context.Entry(x.Priority).State == EntityState.Modified);
EventOrganiserTask.Migrations.All().Select(x => context.Entry(x.TaskStatus).State == EntityState.Modified);
context.Tasks.AddOrUpdate(EventOrganiserTask.Migrations.All());
}
}
The following examples of the instances i'm using for the data.
I create the following methods for the foreign key objects
public static EventTaskType[] All()
{
return new[]
{
GetDeadline(),
GetEmail(),
GetTelephone(),
GetAppointment(),
GetSnailMail(),
};
}
internal static EventTaskType GetDeadline()
{
return new EventTaskType("09974722-D03E-4CA3-BF3A-0AF7F6CA1B67", 1, "Deadline")
{
Icon = ""
}
}
I call the following methods the create the master data.
public static EventOrganiserTask[] All()
{
return new EventOrganiserTask[]
{
GetBookHQ(1, new DateTime(Event.Migrations.EventDate.Year - 1, 10, 1)),
GetFindSponsor(2, new DateTime(Event.Migrations.EventDate.Year - 1, 10, 1)),
GetRegisterEvent(3, new DateTime(Event.Migrations.EventDate.Year - 1, 10, 1)),
GetBookFirstAid(4, Event.Migrations.EventDate.AddMonths(-6))
};
}
NOTE: When creating the master record, I call the method in the foreign key classes each time - which is the crux of the problem where I need to instruct the migration to detach this item.
public static EventOrganiserTask GetRegisterEvent(int id, DateTime date)
{
return new EventOrganiserTask
{
id = id,
Title = "Register event",
Summary = "Register the road race with the region",
DueDate = date,
Priority = EventTaskPriority.Migrations.GetHighPriority(),
Person = Person.Migrations.GetRaceOrganiser(1),
TaskType = EventTaskType.Migrations.GetDefault(),
TaskStatus = TaskStatus.Migrations.GetDefault(),
};
}
NOTE: When I do make changes to the data from the application, the foreign keys are not being updated. This must be related and indicates my entities are not configured correctly.
LATEST:
I'm still tearing my hair out. I've investigated this further and read about the migrations being multi threaded (It was another thread on stackoverflow but I can't find it again). Indeed running the Seed method I supposed is what it says on the tin and is purley for seeding data, so the data is only being added (regardless of AddOrUpdate - what's that all about then) So I've looked at the behaviour regarding the records being created. First of all I called context.SaveChanges() after creating the look up tables. At this point it doesn't created any duplicates as the items are only referenced once. I then let the seed method run the master data - but argggh - I see duplicates (when the instances are called on the master data). But this did flag something up with regard to the order in which it creates the records.
My next step was to create two migrations, but without any success.
I'm hoping somebody picks up this thread soon. I'm tearing my hair out.

Answer 1

Ok so i've finally found my answer. It was clever enough to create the foreign key relationships from the model, but i needed to be explicitly set the foreign key id field. I chose the Fluent API to explicitly set the relationships and I set the value of the id field in the mapping of the object.
modelBuilder.Entity<Task>()
.HasRequired(x => x.Priority)
.WithMany(x => x.Tasks)
.HasForeignKey(x => x.Priority_id);
Here it is in the seed method
public class VeloPointDbConfiguration : DbMigrationsConfiguration<VeloPointDbContext>
{
public VeloPointDbConfiguration()
{
AutomaticMigrationsEnabled = true;
AutomaticMigrationDataLossAllowed = true;
}
protected override void Seed(VeloPointDbContext context)
{
context.TaskPriorities.AddOrUpdate(EventTaskPriority.Migrations.All());
context.TaskStatuses.AddOrUpdate(TaskStatus.Migrations.All());
EventOrganiserTask.Migrations.All().Select(x => context.Entry(x.Priority).State == EntityState.Modified);
EventOrganiserTask.Migrations.All().Select(x => context.Entry(x.TaskStatus).State == EntityState.Modified);
context.Tasks.AddOrUpdate(EventOrganiserTask.Migrations.All());
// Foreign Key relationships
modelBuilder.Entity<EventOrganiserTask>()
.HasRequired(x => x.TaskStatus)
.WithMany(x => x.Tasks)
.HasForeignKey(x => x.TaskStatus_id);
modelBuilder.Entity<Task>()
.HasRequired(x => x.TaskType)
.WithMany(x => x.Tasks)
.HasForeignKey(x => x.TaskType_id);
modelBuilder.Entity<Task>()
.HasRequired(x => x.Priority)
.WithMany(x => x.Tasks)
.HasForeignKey(x => x.Priority_id);
}
}