title: Data not being populated in dropdown using sqlDataSource
body: <p>I need to populate the data from database in Dropdown using sqlDataSource. The SqlDataSource is using a querystring. The data is not being populated in dropdown. Can you please suggest what I am doing wrong here?</p>
  
  <p>Code for Dropdown:   </p>
  
  <pre><code>&lt;ajaxToolkit:ComboBox ID="SelectDropDown1" runat="server" DropDownStyle="DropDownList"
                      AutoCompleteMode="SuggestAppend" AppendDataBoundItems="true" Width="200px" Height="16pt"
                      Font-Size="8pt"  DataSourceID="SqlDataSource1" DataTextField="Rubric"
                   DataValueField="Rubric"&gt;
  
                 &lt;asp:ListItem Value="all"&gt;All&lt;/asp:ListItem&gt;
  
                  &lt;/ajaxToolkit:ComboBox&gt;
  </code></pre>
  
  <p>Code for SqlDataSource:</p>
  
  <pre><code>&lt;asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="&lt;%$ ConnectionStrings:Education_Data %&gt;"
  
          SelectCommand="SELECT DISTINCT [Rubric] FROM [table1] WHERE ([Program] = @Program)"&gt;
  
          &lt;SelectParameters&gt;
              &lt;asp:QueryStringParameter Name="Program" QueryStringField="Program" 
                  Type="String" /&gt;
          &lt;/SelectParameters&gt;
  
      &lt;/asp:SqlDataSource&gt;
  </code></pre>