Data Annotation of Keyless Attribute on class can't override in Fluent API

[jryutzy]

I have an external table that I want to join up in LINQ. Below works to manually create the relationships between the External Table (SoftwareTools_Software) and TagCategory_X_Software IF in the SoftwareTools_Software class I remove the [Keyless] atrtribute. Is there anyway to remove the [Keyless] attribute using modelBuilder? I've tried all kinds of things and if the Keyless attribute is on my class I get this error. I don't want to manually remove from the code that was auto-generated by scaffolding the DB because the next time we scaffold I'd have to remove it again. There should be a way to overwrite the data annotation from modelBuilder. I've tried modelBuilder.HasAnnotation("Keyless", false); and that doesn't seem to work. Keep getting this error.

Message:

    System.NullReferenceException : Object reference not set to an instance of an object.
  Stack Trace: 
    InternalEntityTypeBuilder.SetOrAddForeignKey(ForeignKey foreignKey, InternalEntityTypeBuilder principalEntityTypeBuilder, IReadOnlyList`1 dependentProperties, Key principalKey, String propertyBaseName, Nullable`1 isRequired, Nullable`1 configurationSource)
    InternalEntityTypeBuilder.CreateForeignKey(InternalEntityTypeBuilder principalEntityTypeBuilder, IReadOnlyList`1 dependentProperties, Key principalKey, String propertyBaseName, Nullable`1 required, ConfigurationSource configurationSource)
.....

namespace Master.App
{
    public partial class TagCategory_X_Software
    {
        [ForeignKey(nameof(SoftwareID_EK))]
        [InverseProperty(nameof(SoftwareTools_Software.TagCategory_X_Softwares))]
        public virtual SoftwareTools_Software SoftwareID_EKNavigation { get; set; }
    }
}

namespace CSUMaster.Ext
{
    [MetadataType(typeof(SoftwareTools_SoftwareMetadata))]
    public partial class SoftwareTools_Software
    {
        public SoftwareTools_Software()
	{
            TagCategory_X_Softwares = new HashSet<TagCategory_X_Software>();
        }

        [InverseProperty(nameof(TagCategory_X_Software.SoftwareID_EKNavigation))]
        public virtual ICollection<TagCategory_X_Software> TagCategory_X_Softwares { get; set; }

        internal sealed class SoftwareTools_SoftwareMetadata
	{
            [Key]
            //[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
            public long SoftwareID { get; set; }
        }
    }

public partial class MasterContext
	{

		partial void OnModelCreatingPartial(ModelBuilder modelBuilder)
		{
			modelBuilder.Entity<TagCategory_X_Software>(entity =>
			{
				// foregin key relationship back to SoftwareTools_Software
				entity.HasOne(d => d.SoftwareID_EKNavigation)
				   .WithMany(p => p.TagCategory_X_Softwares)
				   .HasForeignKey(d => d.SoftwareID_EK)
				   .OnDelete(DeleteBehavior.ClientSetNull);
			});

			modelBuilder.Entity<SoftwareTools_Software>(entity =>
			{
				entity.HasKey(e => e.SoftwareID);
			});
		}
	}

Similar issue as #20292 and #24283

[smitpatel]

Use HasKey to define primary for the entity type. That will override KeylessAttribute configuration.

[jryutzy]

Hmm... I think that is what I was trying to do here but for some reason it doesn't work. I set a breakpoint and the code throws the error I showed before this code even fires in the OnModelCreatingPartial method.
modelBuilder.Entity<SoftwareTools_Software>(entity =>
{
entity.HasKey(e => e.SoftwareID);
});

[ajcvickers]

@jryutzy If the code is being scaffolded with [Keyless], then that means EF Core is not finding a suitable key in the database schema. It would be good to understand why this is happening if SoftwareID is a suitable key for this type. Can you post the schema for the two tables involved here so we can look into why the entity type is being scaffolded as keyless?

[jryutzy]

The SoftwareTools_Software table is an External table in SQL Azure DB and as such cannot have a Primary Key. However, a TagCategory_X_Software has an External Key that maps to what would the Primary Key if we could create one on the External table.

I created Navigation Properties on the TagCategory_X_Software and SoftwareTools_Software partial class

This allows me to do this
var list = _tagCategoryService.CSUMasterRepository.CSUMasterContext.TagCategory_X_Softwares .Include(x => x.SoftwareID_EKNavigation) .Where(x => x.Active == true) .ToList();
As long as I comment out the [Keyless] attribute on the external table as shown below

Here is the log showing that EF is in fact joining these two tables.

I don't want to keep manually removing this attribute ever time I scaffold the db.

If I don't remove the [Keyless] attribute I get the error shown in original post and I can't override with Fluent API as it throws the error before the OnModelCreatingPartial method fires.

[ajcvickers]

@jryutzy Thanks, that makes sense; we'll look into the null-ref bug.

Note for triage: it seems to me that scaffolding could handle this case by introducing a key into the EF model based on the properties being at the principal end of the relationship.

[ajcvickers]

See #24369 for updating scaffolding to handle this case.

[slavanap]

@jryutzy have you tried this?

modelBuilder.Entity<SoftwareTools_Software>(entity =>
{
    entity.Metadata.IsKeyless = false;
    entity.HasKey(e => e.SoftwareID);
});

[AndriySvyryd]

Related: #24789