title: Umbraco:custom drop down
body: <p>I am trying to create a custom datatype in Umbraco V7.4.3
  its a Dropdown where the prevalues which will be fetched from Sql statement.
  i am able to create Dropdown</p>
  
  <pre><code> [PropertyEditor(PropertyEditorConstants.SqlDropDownAlias, " Sql DropDown", "/App_Plugins/CustomDataType/DropDown/DropDownEditor.html", ValueType = "TEXT")]
          [PropertyEditorAsset(ClientDependencyType.Javascript, "/App_Plugins/CustomDataType/DropDown/DropDownEditor.controller.js")]
  
       public  class SqlDropDownPropertyEditor:BasePropertyEditor 
              {
                  protected override PreValueEditor CreatePreValueEditor()
                  {
                      return new SqlDropDownPreValueEditor();
                  }
              }
  </code></pre>
  
  <p>any idea on how to provide SQL expression box in the data type and process it ?</p>