using System;

 using System.Data;

 using System.Web;

 using System.Web.UI.WebControls;

 using umbraco.cms.businesslogic.datatype;

 using umbraco.editorControls.userControlGrapper;

 using Microsoft.ApplicationBlocks.Data; 

 namespace UmbracoCreateCustomDatatypeWithWrapper

 {

     public class Demo :  UserControl,  IUsercontrolDataEditor

     {

         [DataEditorSetting("Connection string")]

         public string ConnectionString { get; set; }

         [DataEditorSetting("Select statement")]

         public string SelectStatement { get; set; }

         [DataEditorSetting("Text column")]

         public string TextColumn { get; set; }

         [DataEditorSetting("Value column")]

         public string ValueColumn { get; set; }

         public string umbracoValue;

         protected void Page_Load(object sender, EventArgs e)

         {

             if (Page.IsPostBack)

             {

                 //onsave

                 value = control.SelectedValue;

             }

             else

             {

                 control.DataSource = SqlHelper.ExecuteReader(

                     ConnectionString,

                     CommandType.Text,

                     SelectStatement);

                 control.DataTextField = TextColumn;

                 control.DataValueField = ValueColumn;

                 control.DataBind();

                 control.Items.Insert(, new ListItem(String.Empty, String.Empty));

                 control.SelectedIndex = ;

                 if (value != null)

                     control.SelectedValue = value.ToString();

             }

         }

         public object value

         {

             get

             {

                 return umbracoValue;

             }

             set

             {

                 umbracoValue = value.ToString();

             }

         }

     }

 }