title: WCF NULL vs Not present distinguish
body: <p>In WCF I have a nullable int property on person object. What i want to do is that when the client explicitly passes NULL then i should update the database table to null, if they do NOT send this optional parameter then ignore.     </p>
  
  <p>Example code below. What i have foind is that there seems to be no easy way to do this.</p>
  
  <pre><code>[ServiceContract]
   public interface IPersonRepository
   {
  
    [OperationContract]
     string UpdatePerson(Person person);
  }    
  
  
  
  public class PersonRepository : IPersonRepository
  {
  
    public string UpdatePerson(Person person)
    {
      return person.ToString();
    }
  
  }
  [DataContract]
  public class Person
  {
  
     [DataMember(IsRequired = false)]
     public int? Age{get;set;}
  }
  </code></pre>