Suppose you have a class product, which is work as a table in entity framework. In this class you want to create a primary key. This features provides by System.ComponentModel.DataAnnotations namespace. According to msdn article this namespace provides attributes classes that are used to define metadata. In this example we are creating one or more columns , which is uniquely identified in the table. Suppose, in this table you want to set ProductId as a primary key then simple write 'Key' in brackets before fields. Lets a class
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.ComponentModel.DataAnnotations;
/// <summary>
/// Summary description for Product
/// </summary>
public class Product
{
[Key]
public int ProductId { get; set; } // Primary Key attribute
public string productName { get; set; }
}
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.ComponentModel.DataAnnotations;
/// <summary>
/// Summary description for Product
/// </summary>
public class Product
{
[Key]
public int ProductId { get; set; } // Primary Key attribute
public string productName { get; set; }
}