The MSDN documentation gives a walkthrough of how to update a local database application on the Windows Phone over time. The documentation gives quite a bit of detail but seems to miss a likely scenario. So let’s investigate the process step-by-step.

Initial Version

We are creating the first version of our application and decide that we need a User database table with the following columns: Name (primary key), LastAccessedDate

So we create a User class as follows:

[Table]
public class User : INotifyPropertyChanged, INotifyPropertyChanging
{
  private string name;
  private DateTime? lastAccessed;

  [Column(IsPrimaryKey = true, CanBeNull = false, AutoSync = AutoSync.OnInsert)]
  public string Name
  {
  get { return name; }
  set
    {
      NotifyPropertyChanging("Name");
      name = value;
      NotifyPropertyChanged("Name");
    }
  }

  [Column]
  public DateTime? LastAccessed
  {
    get { return lastAccessed; }
    set
    {
      NotifyPropertyChanging("LastAccessed");
      lastAccessed = value;
      NotifyPropertyChanged("LastAccessed");
    }
  }

  // Version column aids update performance.
  [Column(IsVersion = true)]
  private Binary version;

  // INotifyPropertyChanged Members
  // INotifyPropertyChanging Members
}

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