Get related columns from FK table in a one-to-one related table - EF Core (2) - entity-framework

Question

This should be fairly easy but I am struggling quite a bit.
My situation is as follows:
I have a table (Commodity) with a foreign key to another table (CommodityMaterial). In my GET endpoint I want to retrieve all the column data from Commodity and all the columns from CommodityMaterial as well.
I have set it up as follows:
public class Commodity
{
public long CommodityID { get; set; }
public long CommodityMaterialID { get; set; }
public decimal? SpecficWeight { get; set; }
public OmsCommodityMaterial OmsCommodityMaterial { get; set; }
public ICollection<OmsCommodityMaterial> OmsCommodityMaterials { get; set; }
}
The Foreign key table:
public class CommodityMaterial
{
public long? CommodityMaterialID { get; set; }
public string Name { get; set; }
public long? SortOrder { get; set; }
public Commodity Commodity { get; set; }
}
The FLUENT API:
modelBuilder.Entity<Commodity>(entity =>
{
entity.Property(e => e.CommodityID)
.HasColumnName("CommodityID")
.ValueGeneratedOnAdd();
entity.Property(e => e.CommodityMaterialID)
.HasColumnName("CommodityMaterialID");
entity.Property(e => e.SpecficWeight)
.HasColumnName("SpecficWeight")
.HasColumnType("decimal(18, 2)");
entity.HasOne(a => a.OmsCommodityMaterial)
.WithOne(b => b.Commodity)
.HasForeignKey<Commodity>(b => b.CommodityMaterialID);
});
This creates the proper relationship, a CommodityMaterial (ID) is needed when creating a Commodity.
Now I want to get all values / columns of the Commodity table, but also the related columns of the CommodityMaterial table (CommodityMaterialID, Name and SortOrder). After reading some other posts i found out I should/could use Include to get related data, my GET operation looks as follow:
[HttpGet]
public async Task<IEnumerable<Commodity>> GetTest()
{
return await Context.Commodity.Include(x => x.OmsCommodityMaterials).ToListAsync();
}
However, this still only returns the 3 columns of the Commodity table (CommodityID, CommodityMaterialID, SpecficWeight)
Anyone has a clue what I am doing wrong?
SOLUTION
Ok, I am a bit ashamed, the problem was the fact that I was using a DataContract annotation in my Commodity POCO class, which was omitted in the code above, the OmsCommodityMaterial reference was missing a DataMember attribute thus making it's fields invisible...

Answer 1

Although not an answer per se maybe you would find it yourself here.
Include()/ThenInclude() (Eager loading) is one of three possible solutions. I suggest you explore the other two as well - Explicit and Lazy.
EDIT: Further investigating your code it seems a bit strange to have a collection of entities in a one-to-one relationship. Maybe you would want to use just the class and (this is important!) specify class names in < and > when calling HasOne(). If you use ReSharper, or something similar, such tool suggest name simplification, that is to get rid of explicitly specifying the types when templating fluent methods. This is the next special place when EF gives slightly different meaning to known C# features. The first one is the very well-known virtuals.
HTH

Answer 2

I am a bit ashamed by this, the problem was the fact that I was using a DataContract annotation in my Commodity POCO class, which was omitted in the code above, the OmsCommodityMaterial reference was missing a DataMember attribute thus making it's fields invisible...