We have a enum Supplier
But now we need to also have some Domain data on that relation
So in 99.9% in the domain code we doe operations on the enum like product.Supplier == Suppliers.FedEx
But now we also have added product.SupplierInfo.CanAdjustPickupTime
where SupplierInfo
is a Entity and not just a simple enum type.
I have tried these configs
Property(p => p.Supplier)
.IsRequired()
.HasColumnName("SupplierId");
HasRequired(p => p.SupplierInfo)
.WithMany()
.HasForeignKey(p => p.Supplier); //I have also tried casting to int doing .HasForeignKey(p => (int)p.Supplier)
This will fail with
The ResultType of the specified expression is not compatible with the required type. The expression ResultType is 'MyApp.Model.Suppliers' but the required type is 'Edm.Int32'. Parameter name: keyValues[0]
Also tried
Property(l => l.Supplier)
.IsRequired()
.HasColumnName("SupplierId");
HasRequired(p => p.SupplierInfo)
.WithMany()
.Map(m => m.MapKey("SupplierId"));
This will offcourse give the good old
One or more validation errors were detected during model generation:
SupplierId: Name: Each property name in a type must be unique. Property name 'SupplierId' is already defined.
I could offcourse define SupplierId as a Property use that with HasForeignKey
But then I need to change to .SuppliedId == (int)Suppliers.FedEx
etc. Not really a solution.
I could also add a property enum that uses the SupplierId property as backing field, but this will not work with Expressions since it needs to use real mapped DB properties
Any ideas?
The best way I have found to deal with this scenario is to map Supplier as a regular domain object and create a separate class of known supplier IDs.
public class KnownSupplierIds
{
public const int FedEx = 1;
public const int UPS = 2;
// etc.
}
if (product.Supplier.SupplierId == KnownSupplierIds.Fedex) { ... };
When your code needs to check the supplier, it can compare the IDs; when you need additional info from the domain model you just load the Supplier. The reason I prefer using a class of constants instead of an enum is that the pattern works for string comparisons also and there's no need to cast.