Buscar datos en la base de datos

Este es el método más simple sin el uso de modelos de membresía. Este es un método simple que utiliza el lector de datos.

    SqlDataReader sdrDatanew = null;
    string strnew;
    string connectionString = WebConfigurationManager.ConnectionStrings["Gen_LicConnectionString"].ConnectionString;
    SqlConnection connew = new SqlConnection(connectionString);
    connew.Open();
    strnew = "select User_Type from User_Details where User_Type='" + ddlUserSel.SelectedItem.Value + "' AND LoginID = '" + txtUserName.Text + "' AND Password = '" + txtPassword.Text + "'";
    SqlCommand sqlCommnew = new SqlCommand(strnew, connew);
    sdrDatanew = sqlCommnew.ExecuteReader();

    int userType = 0;

    if (sdrDatanew.HasRows)
    {
        if (sdrDatanew.Read())
        {
            userType = Convert.ToInt32(sdrDatanew["User_Type"].ToString());
        }
    }

    switch (userType)
    {
        case 0:
            Response.Redirect("Lic_Gen.aspx");
            break;
        case 1:
            Response.Redirect("Cust_Page.aspx");
            break;
        default:
            Console.WriteLine("Invalid User/Password");
            Console.ReadLine();
            break;
    }

    connew.Close();