Move source code into "Source" folder

Source/DataLayer/Configurations/BookConfig.cs

@@ -0,0 +1,71 @@
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Metadata.Builders;
+
+namespace DataLayer.Configurations
+{
+    internal class BookConfig : IEntityTypeConfiguration<Book>
+    {
+        public void Configure(EntityTypeBuilder<Book> entity)
+        {
+            entity.HasKey(b => b.BookId);
+            entity.HasIndex(b => b.AudibleProductId);
+
+            entity.OwnsOne(b => b.Rating);
+
+            //
+            // CRUCIAL: ignore unmapped collections, even get-only
+            //
+            entity.Ignore(nameof(Book.Authors));
+            entity.Ignore(nameof(Book.Narrators));
+			//// these don't seem to matter
+			//entity.Ignore(nameof(Book.AuthorNames));
+			//entity.Ignore(nameof(Book.NarratorNames));
+			//entity.Ignore(nameof(Book.HasPdfs));
+
+			// OwnsMany: "Can only ever appear on navigation properties of other entity types.
+			//  Are automatically loaded, and can only be tracked by a DbContext alongside their owner."
+			entity
+				.OwnsMany(b => b.Supplements, b_s =>
+				{
+					b_s.WithOwner(s => s.Book)
+						.HasForeignKey(s => s.BookId);
+					b_s.HasKey(s => s.SupplementId);
+				});
+            // even though it's owned, we need to map its backing field
+            entity
+                .Metadata
+                .FindNavigation(nameof(Book.Supplements))
+                .SetPropertyAccessMode(PropertyAccessMode.Field);
+
+			// owns it 1:1, store in separate table
+			entity
+				.OwnsOne(b => b.UserDefinedItem, b_udi =>
+				{
+					b_udi.WithOwner(udi => udi.Book)
+						.HasForeignKey(udi => udi.BookId);
+					b_udi.Property(udi => udi.BookId).ValueGeneratedNever();
+					b_udi.ToTable(nameof(Book.UserDefinedItem));
+
+					// owns it 1:1, store in same table
+					b_udi.OwnsOne(udi => udi.Rating);
+				});
+
+			entity
+                .Metadata
+                .FindNavigation(nameof(Book.ContributorsLink))
+                // PropertyAccessMode.Field : Contributions is a get-only property, not a field, so use its backing field
+                .SetPropertyAccessMode(PropertyAccessMode.Field);
+
+            entity
+                .Metadata
+                .FindNavigation(nameof(Book.SeriesLink))
+                // PropertyAccessMode.Field : Series is a get-only property, not a field, so use its backing field
+                .SetPropertyAccessMode(PropertyAccessMode.Field);
+
+            entity
+                .HasOne(b => b.Category)
+                .WithMany()
+                .HasForeignKey(b => b.CategoryId);
+		}
+    }
+}