使用延迟加载删除具有导航属性的实体时，DbUpdateException

Question

I have the following entity:

public class MyEntity
{
    public Guid? Id { get; set; }
    public string Name { get; set; }
    public virtual ApplicationUser User { get; set; }
}

And I'm trying to remove it this way:

var myEntity = await db.MyEntities.FindAsync(id);

if (myEntity != null)
{
    db.MyEntities.Remove(myEntity);
    await db.SaveChangesAsync();
}

And it's giving me this error:

An error occurred while saving entities that do not expose foreign key properties for their relationships

If I manually .Include() the navigation properties, it works fine.

My question is two fold, why is Lazy Loading not loading whatever properties are necessary for this to just work, and is there a proper way to remove entities without having to manually .Include() every single navigation property beforehand?

Answer 1

It is as I suspected, lazy loading wasn't working anymore because the dbcontext was either closed or in some closing state. I fixed all my problems by switching to a singe DbContext per request (stored in HttpContext.Current.Items)