using System;

using System.ComponentModel.DataAnnotations;

using System.ComponentModel.DataAnnotations.Schema;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

    }

}

​

public class Product

    {

        [Key]

        [HiddenInput(DisplayValue = false)]

        [DatabaseGenerated(DatabaseGeneratedOption.Identity)]

        public int ProductId { get; set; }

​

        [Required(ErrorMessage = "Please enter a product name")]

        [MaxLength(128)]

        public string Name { get; set; }

​

        [Required(ErrorMessage = "Please enter a description")]

        [DataType(DataType.MultilineText)]

        public string Description { get; set; }

​

        [Required(ErrorMessage = "Please enter a price")]

        [Range(0.01, double.MaxValue, ErrorMessage = "Please enter a positive price")]

        public decimal Price { get; set; }

​

        [Required(ErrorMessage = "Please specify a category")]

        public string Category { get; set; }

    }