Complex Types — EF Core 8+

Gerçek Senaryo: Ürün fiyatı — para birimi ile birlikte

decimal Price yazmak yetmez — hangi para birimi? Money tipini hem Product hem Order hem başka entityler kullanabilir.

// --- Tipler ---

public record Money(decimal Amount, string Currency);   // record → immutable

public class Product
{
    public int    Id        { get; set; }
    public string Name      { get; set; }
    public Money  Price     { get; set; }   // satış fiyatı
    public Money  CostPrice { get; set; }   // maliyet fiyatı
}

public class Order
{
    public int   Id    { get; set; }
    public Money Total { get; set; }   // aynı Money tipi burada da kullanılıyor
}

// --- Config ---

public class ProductConfiguration : IEntityTypeConfiguration<Product>
{
    public void Configure(EntityTypeBuilder<Product> builder)
    {
        builder.ToTable("Products");
        builder.HasKey(p => p.Id);
        builder.Property(p => p.Name).IsRequired().HasMaxLength(200);

        builder.ComplexProperty(p => p.Price, price =>
        {
            price.Property(m => m.Amount)  .HasColumnName("Price_Amount")  .HasPrecision(18, 2);
            price.Property(m => m.Currency).HasColumnName("Price_Currency").HasMaxLength(3);
        });

        builder.ComplexProperty(p => p.CostPrice, cost =>
        {
            cost.Property(m => m.Amount)  .HasColumnName("Cost_Amount")  .HasPrecision(18, 2);
            cost.Property(m => m.Currency).HasColumnName("Cost_Currency").HasMaxLength(3);
        });
    }
}

Oluşan SQL:

CREATE TABLE [Products] (
    [Id]             INT           IDENTITY(1,1) NOT NULL,
    [Name]           NVARCHAR(200) NOT NULL,
    [Price_Amount]   DECIMAL(18,2) NOT NULL,
    [Price_Currency] NVARCHAR(3)   NOT NULL,
    [Cost_Amount]    DECIMAL(18,2) NOT NULL,
    [Cost_Currency]  NVARCHAR(3)   NOT NULL,
    CONSTRAINT [PK_Products] PRIMARY KEY CLUSTERED ([Id])
);

CREATE TABLE products (
    id             INT           GENERATED BY DEFAULT AS IDENTITY,
    name           VARCHAR(200)  NOT NULL,
    price_amount   NUMERIC(18,2) NOT NULL,
    price_currency VARCHAR(3)    NOT NULL,
    cost_amount    NUMERIC(18,2) NOT NULL,
    cost_currency  VARCHAR(3)    NOT NULL,
    CONSTRAINT pk_products PRIMARY KEY (id)
);

Örnek veri:

Kullanımda:

var product = new Product
{
    Name      = "Laptop",
    Price     = new Money(25000, "TRY"),
    CostPrice = new Money(18000, "TRY")
};

// LINQ sorgusu — EF SQL'e çevirir
var pahalılar = context.Products
    .Where(p => p.Price.Amount > 10000 && p.Price.Currency == "TRY")
    .ToList();

-- EF'in ürettiği SQL:
SELECT [p].[Id], [p].[Name], [p].[Price_Amount], [p].[Price_Currency], 
       [p].[Cost_Amount], [p].[Cost_Currency]
FROM [Products] AS [p]
WHERE [p].[Price_Amount] > 10000.0 AND [p].[Price_Currency] = N'TRY';

-- EF'in ürettiği SQL:
SELECT p.id, p.name, p.price_amount, p.price_currency, 
       p.cost_amount, p.cost_currency
FROM products AS p
WHERE p.price_amount > 10000.0 AND p.price_currency = 'TRY';

Owned Entity ile Complex Type farkı

🆕 EF Core 10 ile Complex Types artık tavsiye edilen yaklaşım:

• JSON mapping (b.ComplexProperty(c => c.Address, c => c.ToJson()))
• Struct desteği (identity olmayan value object'ler için doğal)
• Optional complex types (Address?)
• ExecuteUpdateAsync ile bulk güncelleme
• Owned entity'lerdeki "aynı referans atama" sorunu yok (value semantics)