Question

I am using the code at MembershipDataContext to change username in aspnet_user table in my web form code behind.
But it is not working because MembershipDataContext namespace could not be found.
Google search but no result.

Thanks

UPDATE:

public bool ChangeUserName(Guid userId, string newUserName)
{
    bool success = false;
    newUserName = newUserName.Trim();

    // Make sure there is no user with the new username
    if (Membership.GetUser(newUserName) == null)
    {
        MembershipUser u = Membership.GetUser(userId);
        string oldUsername = u.UserName;
        // get current application

        MembershipDataContext context = new MembershipDataContext ();
        aspnet_User userToChange = (from user in context.aspnet_Users
                                    where user.UserId == userId
                                    select user).FirstOrDefault();

        if (userToChange != null)
        {
            userToChange.UserName = newUserName;
            userToChange.LoweredUserName = newUserName.ToLower();

            context.SubmitChanges();

            // ASP.NET Issues a cookie with the user name. 
            // When a request is made with the specified cookie, 
            // ASP.NET creates a row in aspnet_users table.
            // To prevent this sign out the user and then sign it in

            string cookieName = FormsAuthentication.FormsCookieName;
            HttpCookie authCookie = 
              HttpContext.Current.Request.Cookies[cookieName];

            FormsAuthenticationTicket authTicket = null;

            try
            {
                authTicket = 
                    FormsAuthentication.Decrypt(authCookie.Value);

                FormsIdentity formsIdentity = 
                    new FormsIdentity(
                        new FormsAuthenticationTicket(
                            authTicket.Version, 
                            newUserName, 
                            authTicket.IssueDate, 
                            authTicket.Expiration, 
                            authTicket.IsPersistent, 
                            authTicket.UserData));

                string y = HttpContext.Current.User.Identity.Name;
                string[] roles = 
                    authTicket.UserData.Split(new char[] { '|' });
                System.Security.Principal.GenericPrincipal genericPrincipal = 
                    new System.Security.Principal.GenericPrincipal(
                                                        formsIdentity, 
                                                        roles);

                HttpContext.Current.User = genericPrincipal;
            }
            catch (ArgumentException ex)
            {
                // Handle exceptions
            }
            catch( NullReferenceException ex)
            {
                // Handle exceptions
            }

            FormsAuthentication.SignOut();
            HttpContext.Current.Session.Abandon();
            FormsAuthentication.SetAuthCookie(newUserName, false);
            success = true;
        }
    }

    return success;
}

Answer 1

The code from the question you refer to defines a Linq to SQL entity data context named MembershipDataContext (which makes it a definition of DataContext). There isn’t a built in type (that I’m aware of or could find) named MembershipDataContext.

Here is another example of a project which does the same thing (dbml definition included).