title: ObjectDataSource FilterExpression not working with multiple parameters
body: <p>I have an ObjectDataSource that is binding to my GridView just fine.</p>
  
  <p>I also have two dropdown list boxes that call an ApplyFilterExpression function.</p>
  
  <p>They both work independently, but when i set both dropdown with values i get no results. But i KNOW that there should be results. What am i doing wrong here?</p>
  
  <pre><code>&lt;asp:ObjectDataSource ID="dsLogs" runat="server" SelectMethod="GetDTAll" 
      TypeName="LogManager.LogRepository" 
      SelectCountMethod="GetAllCount" &gt;
      &lt;SelectParameters&gt;
          &lt;asp:Parameter DefaultValue="DESC" Name="sortOrder" Type="String" /&gt;
          &lt;asp:Parameter DefaultValue="timestamp" Name="orderBy" Type="String" /&gt;
          &lt;asp:Parameter DefaultValue="1" Name="startRowIndex" Type="Int32" /&gt;
          &lt;asp:Parameter DefaultValue="1000" Name="maximumRows" Type="Int32" /&gt;
      &lt;/SelectParameters&gt;
  &lt;/asp:ObjectDataSource&gt;
  
  private void ApplyFilterExpression()
  {
      dsLogs.FilterExpression = null;
      bool hasFilter = false;
  
      if (ddlTypes.SelectedIndex != 0)
      {
          dsLogs.FilterExpression = "type='" + ddlTypes.SelectedValue + "'";
          hasFilter = true;
      }
  
      if (ddlUsers.SelectedIndex != 0)
      {
          if (hasFilter)
          {
              dsLogs.FilterExpression += " AND username='" + ddlUsers.SelectedValue + "'";
          }
          else
          {
              dsLogs.FilterExpression = "username='" + ddlUsers.SelectedValue + "'";
              hasFilter = true;
          }
      }
      ViewState["FiltExp"] = (string)dsLogs.FilterExpression;
  }
  </code></pre>