protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity <Auction>()
.HasOne(auction => auction.AuctionDetail)
.WithOne(auctionDetail => auctionDetail.Auction)
.HasForeignKey <AuctionDetail>(auctionDetail => auctionDetail.AuctionId);
// Seed data.
DataSeeder seeder = new DataSeeder();
List <Make> makes = seeder.GenerateCarMakes();
modelBuilder.Entity <Make>().HasData(makes);
List <Model> models = seeder.GenerateCarModels();
modelBuilder.Entity <Model>().HasData(models);
List <Trim> trims = seeder.GenerateCarTrims();
modelBuilder.Entity <Trim>().HasData(trims);
}