title: Migrate data using FluentMigrator
body: <p>I use FluentMigrator in my project.
  And now I Add new column in table and how I can update data in this column by SQL query?</p>
  
  <pre><code>public override void Up()
  {
      Alter.Table("Images").AddColumn("Item_id").AsInt32().Nullable();
      //do something like "Update Images img set img.Item_id=(Select i.Id 
      //from Items i where i.Image=img.Id)"
  }
  public override void Down()
  {
      Delete.Column("Item_id").FromTable("Images");
  }
  </code></pre>