How to extract value returned from query, assign it to user as Roles.AddUserToRole?

Nostromo77 · September 20th, 2011, 05:49 PM

I'm stuck on what might be some simple ASP.NET syntax: I have a page that allows a user to enter a code into a textbox, and then checks that code against a database table to return the values of one specific table row (if the code was correct) or an error message (if the code doesn't exist in the database table).

The page functions without a problem, and I can display the results of the one returned table row in a DetailsView control.

What I want to do, is to display some of the returned data in a Label or Literal control, and also to assign one of the returned string values ("Role") as the logged-in users new role, using Roles.AddUserToRole. So, for example, if the user enters the valid code 12Ab34Cd, the query will return the values:

EnrollmentCode:12Ab34Cd
Role:student

...I want to assign the string "student" as the user's new membership role, but I'm not sure how to do this. I'm using the standard ASP.NET membership provider, and all of the "Role" strings returned by the query are preexisting, valid membership roles that I have already created.

Thanks for any advice.

The aspx page's code is:

Code:

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="test_validate.aspx.cs" Inherits="testvalidation_test_validate" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title>Untitled Page</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
    <h2>Test Validate</h2>
  
         Enroll code: 
         <asp:TextBox 
            ID="txtEnrollCode" 
            runat="server" />
         <asp:Button 
            ID="btnValidate" 
            runat="server" 
            Text="Go" />
         <br />
         <asp:RequiredFieldValidator 
            ID="reqval_txtTeam" 
            runat="server" 
            ErrorMessage="You must enter an enrollment code."
            ControlToValidate="txtEnrollCode" 
            Display="Dynamic" />
         <br />
         <asp:RegularExpressionValidator 
            ID="revEnrollCode" 
            runat="server"
            ErrorMessage="Your enrollment code must consist of eight characters, with no spaces."
            ControlToValidate="txtEnrollCode" 
            ValidationExpression="[a-zA-Z0-9]{8}">
         </asp:RegularExpressionValidator>
         <br />
         <asp:CustomValidator 
            ID="custval_txtEnrollCode" 
            runat="server" 
            ErrorMessage="The enrollment code you entered cannot be found in our database; please try again."
            ControlToValidate="txtEnrollCode" 
            Display="Dynamic" 
            OnServerValidate="custval_txtEnrollCode_ServerValidate" />
         <asp:Label 
            ID="lblResult" 
            runat="server" 
            EnableViewState="False" />
         <asp:SqlDataSource 
            ID="SqlDataSourceEnrollCodes" 
            runat="server" 
            ConnectionString="<%$ ConnectionStrings:NSH_ONLINE_TOLConnectionString %>"  
            SelectCommand="SELECT [EnrollmentCode], [Role] FROM [enrollmentcodes] WHERE ([EnrollmentCode] = @EnrollmentCode)" 
            onselecting="SqlDataSourceEnrollCodes_Selecting">
             <SelectParameters>
                 <asp:ControlParameter 
                    ControlID="txtEnrollCode" 
                    Name="EnrollmentCode" 
                    PropertyName="Text" 
                    Type="String" />
             </SelectParameters>
         </asp:SqlDataSource>
        
        <asp:DetailsView 
            ID="DetailsView1" 
            runat="server" 
            Height="50px" 
            Width="125px" 
            AutoGenerateRows="False" 
            DataSourceID="SqlDataSourceEnrollCodes">
            <Fields>
                <asp:BoundField 
                    DataField="EnrollmentCode" 
                    HeaderText="EnrollmentCode" 
                    SortExpression="EnrollmentCode" />
                <asp:BoundField 
                    DataField="Role" 
                    HeaderText="Role" 
                    SortExpression="Role" />
            </Fields>
        </asp:DetailsView>
    </div>
    </form>
</body>
</html>

The Codebehind is:

Code:

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.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;

public partial class testvalidation_test_validate : System.Web.UI.Page
{
    protected void custval_txtEnrollCode_ServerValidate(object source, ServerValidateEventArgs args)
    {
        args.IsValid = false;
        foreach (DataRowView drv in SqlDataSourceEnrollCodes.Select(DataSourceSelectArguments.Empty))
        {
            if (drv["EnrollmentCode"].ToString() == args.Value)
            {
                args.IsValid = true;
                break;
            }
        }

        if (args.IsValid)
            lblResult.Text = "The enrollment code you entered was found; the code is:" ;
    }
}

Imar · September 21st, 2011, 06:29 AM

Personally, I wouldn't use DetailsView and SqlDataSource controls for this. While you probably could dig into the content of the DetailsView to find the values, it'll become messy quite quickly.

Instead, I would access the database from Code Behind using plain ADO.NET objects (like the SqlConnection and SqlCommand), LINQ to SQL or Entity Framework. This also makes it easier to abstract your logic to separate classes in case you need to reuse it.

Cheers,

Imar

Nostromo77 · September 26th, 2011, 02:24 PM

I will try that - thank you!