So I’ve inherited an app that I’ve recently upgraded from .NET Core 2 to .NET 8. It uses entityframework and a lot of .OwnsOne().

After updating I ran into the problem that, in the previous version of EF (2.2.6) whenever I select anything that uses those I get an instance of a class with everything set to default. This has changed and it will only create an instance of a class if I tell it to, or I create that class if it’s null. As in I’d have to find all places that uses that navigation property and do

protected void UpdateSelf(Tour tour) 
{
  // Has a lot of property updates that I've ommitted
  // It also calls .UpdateSelf() on other owned types. In this case they would have already be created with values, and won't be null on select

  if (Completion == null)
    Completion = new Completion(null, null);

  Completion.UpdateSelf(tour.Completion);
}

To avoid exceptions. The class itself is this:

    [Owned]
    public class Completion : IEquatable<Completion>
    {
#nullable enable
        public DateTime? CompletedTime { get; private set; }
        public string? Comment { get; private set; }
        //private Completion() { }

        public Completion(DateTime? completedTime, string? comment)
        {
            CompletedTime = completedTime;
            Comment = comment;
        }
#nullable disable

        internal void UpdateSelf(Completion completion)
        {
            if (completion == null) return;
            CompletedTime = completion.CompletedTime;
            Comment = completion.Comment;
        }
        
        // And the IEquatable implementation
    }

And is configured on the entity like so:

builder.OwnsOne(t => t.Completion);

And selecting it

var target = await _dbContext.PlantToDepotTours
  .Where(t => t.Id == dto.Id)
  .FirstOrDefaultAsync();

Not really anything groundbreaking. But I’d really like to know if there was a way to configure EF to make Completion not be null on select. It’s not marked as nullable either.

I also know I can do

builder.OwnsOne(t => t.Completion);
builder.Navigation(t => t.Completion).IsRequired().AutoInclude();

But that would require me to add it on all the navigation properties, and it doesn’t seem like it would produce the same behaviour either.