title: These columns don't currently have unique values
body: <p>I face the following problem : when i try to bind <a href="http://demos.telerik.com/aspnet-ajax/treeview/examples/functionality/checkboxes/defaultcs.aspx" rel="nofollow noreferrer">Telerik Treeview</a></p>
  
  <blockquote>
    <p>These columns don't currently have unique values.</p>
  </blockquote>
  
  <hr>
  
  <p>My code :</p>
  
  <pre><code>protected void BindRTV()
  {
      rtv_acd.DataTextField = "name";
      rtv_acd.DataValueField = "main_id";
      rtv_acd.DataFieldID = "main_code";
      rtv_acd.DataFieldParentID = "father_code";
      rtv_acd.DataSource = dt;
      rtv_acd.DataBind();
  }
  </code></pre>
  
  <hr>
  
  <p>Data snapshot :</p>
  
  <p><img src="https://i.stack.imgur.com/9NVu6.png" alt="enter image description here"></p>
  
  <p>How to fix this problem, i know that the <code>main_code</code> is repetitive but i want that . </p>