ASP.NET Newbie - can't update DataGrid from SQL database -

i'm new asp.net , trying pull simple web app allow users view (for that) data sql database based on selections listbox , dropdown. idea click on button after selections made return database results based on stored proc being passed list , dropdown selections parameters. think i'm pretty close can't seem return results datagrid designated purpose. c# code i'm running below. appreciated!!!

using system; using system.collections; using system.configuration; using system.data; using system.linq; using system.web; using system.web.security; using system.web.ui; using system.web.ui.webcontrols; using system.web.ui.webcontrols.webparts; using system.web.ui.htmlcontrols; using system.xml.linq; using system.windows.forms; using system.data.sqlclient;  namespace timeline_analytics_app_test {     public partial class default : system.web.ui.page     {         protected void page_load(object sender, eventargs e)         {          }          protected void button1_click(object sender, eventargs e)         {             string host = listbox1.selectedvalue;             string test = dropdownlist1.selectedvalue;             this.sqldatasource3.selectcommand = "exec dbo.test_result_detail '" + host + "', " + test;             //messagebox.show(this.sqldatasource3.selectcommand);             //this.gridview1.databind();              string querystring = sqldatasource3.selectcommand;              messagebox.show(querystring);              dataset ds = getdata(querystring);              if (ds.tables.count > 0)             {                 //messagebox.show("1");                 gridview1.datasource = ds;                 //messagebox.show("2");                 gridview1.databind();                 //messagebox.show("3");             }             else             {                 messagebox.show("unable connect database.");             }          }          dataset getdata(string querystring)         {              // retrieve connection string stored in web.config file.             string connectionstring = configurationmanager.connectionstrings["timeline_analyticsconnectionstring3"].connectionstring;              dataset ds = new dataset();              try             {                 // connect database , run query.                 sqlconnection connection = new sqlconnection(connectionstring);                 sqldataadapter adapter = new sqldataadapter(querystring, connection);                  // fill dataset.                 adapter.fill(ds);             }             catch (exception ex)             {                 // connection failed. display error message.                 messagebox.show("unable connect database.");             }              return ds;         }     } } 

add-on:

my default.aspx:

<%@ page language="c#" masterpagefile="~/tatrrt.master" autoeventwireup="true" codebehind="default.aspx.cs" inherits="timeline_analytics_app_test.default" title="untitled page" %> <asp:content id="content1" contentplaceholderid="head" runat="server"> </asp:content> <asp:content id="content2" contentplaceholderid="contentplaceholder1" runat="server">  <asp:scriptmanager id="scriptmanager1" runat="server" /> <asp:updatepanel id="updatepanel1" runat="server"> <contenttemplate>      <%--host list box--%>     <div>         <h4 style="font-family:verdana; font-size:10pt; position:absolute;left:10px;top:140px">please select host want review</h4>         <asp:listbox id="listbox1" runat="server" datasourceid="sqldatasource1" style="font-family:verdana; font-size:10pt; position:absolute;left:10px;top:180px"             datatextfield="host" datavaluefield="host" height="150" width="320"></asp:listbox>         <asp:sqldatasource id="sqldatasource1" runat="server"              connectionstring="<%$ connectionstrings:timeline_analytics_app_testconnectionstring %>"             selectcommand="select distinct host test_summary category null , responsive = 1">         </asp:sqldatasource>         <br></br>     </div>     <%--test dropdown--%>     <div>         <h4 style="font-family:verdana; font-size:10pt; position:absolute;left:350px;top:140px">please select test want review</h4>         <asp:dropdownlist id="dropdownlist1" runat="server" datasourceid="sqldatasource2" style="font-family:verdana; font-size:10pt; position:absolute;left:350px;top:180px"             datatextfield="test_name" datavaluefield="test_name" width="320">         </asp:dropdownlist>         <asp:sqldatasource id="sqldatasource2" runat="server"              connectionstring="<%$ connectionstrings:timeline_analytics_app_testconnectionstring2 %>"             selectcommand="select distinct cast(right(reverse(right(reverse(test_name), 8)), 2) int) test_name test_summary order cast(right(reverse(right(reverse(test_name), 8)), 2) int)">          </asp:sqldatasource>      <%--test result summary--%>     <asp:gridview id="gridview1" runat="server"              style="font-family:verdana; font-size:10pt; position:absolute;left:10px;top:350px" allowpaging="true"              autogeneratecolumns="false">             <%--datasourceid="sqldatasource3"--%>     </asp:gridview>     <asp:sqldatasource id="sqldatasource3" runat="server"          connectionstring="<%$ connectionstrings:timeline_analyticsconnectionstring3 %>"          selectcommand="">     </asp:sqldatasource>     </div>     <asp:button id="button1" runat="server" text="retrieve results"          style="font-family:verdana; font-size:10pt; position:absolute;left:680px;top:180px"          onclick="button1_click"/>  </contenttemplate> </asp:updatepanel>  </asp:content> 

your problem autogeneratecolumns="false" , have no columns defined in markup, when gridview data binds has nothing bind to.

the easiest fix set autogeneratecolumns true, this:

autogeneratecolumns="true" 

note: make column names same database field, may or may not want.

to more control on gridview columns, check out gridview column property msdn documentation