Add SetDeleteBehavior option to EnumLookupOptions

[BalintBanyasz]

EF Core DeleteBehavior defaults to DeleteBehavior.Cascade and currently there is no way to change this setting globally. The new SetDeleteBehavior option allows users to specify the DeleteBehavior for the generated FKs while keeping Cascade as the default behavior for compatibility.

One potential use case is when introducing the auto-generated FK with the default Cascade behavior would result in an error with SQL Server (Introducing FOREIGN KEY constraint 'fk_two' on table 'table2' may cause cycles or multiple cascade paths...).

[pergerch]

Thanks for your contribution. This is now included in release 1.3.0

[TAGC]

Is there a way to override this for a single enum relationship while keeping the default FK delete behaviour for enums as Cascade? E.g.

public class ProfileRecordConfiguration : IEntityTypeConfiguration<ProfileRecord>
{
    public void Configure(EntityTypeBuilder<ProfileRecord> builder)
    {
        builder.ToTable(nameof(ProfileRecord));

        builder.HasKey(nameof(ProductConsultant) + "Id", nameof(ProfileRecord.Period));

        builder.Property(x => x.Period).HasConversion(
            x => (int) x,
            x => new Period(x));

        builder.HasOne<ProductConsultant>().WithMany();
        builder.HasOne(x => x.CommissionPlan).WithMany().OnDelete(DeleteBehavior.Restrict);

        // VehicleSaleType property has enum type PrimaryVehicleSaleType, and should use a different
        // FK deletion behaviour from the default enum deletion behaviour of `Cascade`
        //builder.HasOne(x => x.VehicleSaleType).WithMany().OnDelete(DeleteBehavior.Restrict);
    }
}

[TAGC]

An ugly workaround that I'm using at present:

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    var enumLookupOptions = EnumLookupOptions.Default.SetNamingScheme(x => x.Pascalize());

    modelBuilder.ApplyConfigurationsFromAssembly(typeof(CommissionsContext).Assembly);
    // ...
    modelBuilder.ConfigureEnumLookup(enumLookupOptions);
    FixProfileRecordConfiguration(modelBuilder);
    // ...
}

private static void FixProfileRecordConfiguration(ModelBuilder modelBuilder)
{
    var profileRecordBuilder = modelBuilder.Entity<ProfileRecord>();

    var primaryVehicleSaleTypeRelationship = profileRecordBuilder.Metadata.GetForeignKeys()
        .Single(x => x.PrincipalEntityType.ClrType == typeof(EnumWithNumberLookup<PrimaryVehicleSaleType>));

    primaryVehicleSaleTypeRelationship.DeleteBehavior = DeleteBehavior.Restrict;
}