定石3: EF6 + Code First Migrationの最小コード

// ✅定石3-a: DbContextの定義
using System.Data.Entity;
 
public class MyDbContext : DbContext
{
    public MyDbContext(): base("name=MyDb"){ }   // Web.configのMyDb接続文字列を参照
 
    public DbSet<Customer> Customers { get; set; }
    public DbSet<Order> Orders { get; set; }
}
 
public class Customer
{
    public int Id { get; set; }
    public string Name { get; set; }
    public string Status { get; set; }
    public virtual ICollection<Order> Orders { get; set; }   // Lazy Loading
}
 
public class Order
{
    public int Id { get; set; }
    public int CustomerId { get; set; }
    public decimal Amount { get; set; }
    public DateTime CreatedAt { get; set; }
    public virtual Customer Customer { get; set; }
}