Hi,

I helped myself with some resolved discussions on this forum.

But now I'm having trouble finding a tutorial that shows how to implement Cascading DropDownList from a Database.

I'm using ASP.NET MVC but not using EntityFramework with C#.

As of now, I'm able to retrieve the data from my database to my two DropDownList fine.

What I would like to be able to accomplish is to have the user select a UOR first which would then display all Cabina related to that UOR.

The DropDownList Cabina should be disabled and only activated when you select a value from DropDownList UOR.

Any help would be greatly appreciated.

My code below 

    public class HomeController : Controller
    {
        [HttpPost]
        public ActionResult Index(PersonModel person)
        {
            var fruitsRepo = new FruitsRepository();
            var fruits = fruitsRepo.GetAll();
            var fruitsSelecteListItems = fruits.Select(fruit => new SelectListItem
            {
                Text = fruit.Name,
                Value = fruit.Code
            }).ToList();
            person.Fruits = fruitsSelecteListItems;

            var cabinasRepo = new CabinaRepository();
            var cabinas = cabinasRepo.GetAll();
            var cabinasSelecteListItems = cabinas.Select(cabina => new SelectListItem
            {
                Text = cabina.NomeCabina,
                Value = cabina.CodiceCabina
            }).ToList();
            person.Nodo = cabinasSelecteListItems;

            return View(person);
        }

        public class Cabina
        {
            public string NomeCabina { get; }
            public string CodiceCabina { get; }

            public Cabina(string nomecabina, string codicecabina)
            {
                NomeCabina = nomecabina;
                CodiceCabina = codicecabina;
            }
        }

        public class CabinaRepository
        {
            public List<Cabina> GetAll()
            {
                string sql;

                var nodo = new List<Cabina>();

                string constr = ConfigurationManager.ConnectionStrings["cn"].ConnectionString;

                using (MySqlConnection con = new MySqlConnection(constr))
                {
                    sql = @String.Format(" SELECT * FROM `tbl_1` ");
                    sql += String.Format("  WHERE UOR = '1FU1'; ");

                    using (MySqlCommand cmd = new MySqlCommand(sql))
                    {
                        cmd.Connection = con;
                        con.Open();

                        using (MySqlDataReader sdr = cmd.ExecuteReader())
                        {
                            while (sdr.Read())
                            {
                                var cabina = new Cabina(sdr["Nodo_Cod"].ToString(),
                                    sdr["Nodo_Den"].ToString());
                                nodo.Add(cabina);
                            }
                        }
                        con.Close();
                    }
                }

                return nodo;
            }
        }

        public class Fruit
        {
            public string Code { get; }
            public string Name { get; }

            public Fruit(string code, string name)
            {
                Code = code;
                Name = name;
            }
        }

        public class FruitsRepository
        {
            public List<Fruit> GetAll()
            {
                string sql;

                var fruits = new List<Fruit>();

                string constr = ConfigurationManager.ConnectionStrings["cn"].ConnectionString;

                using (MySqlConnection con = new MySqlConnection(constr))
                {
                    sql = @String.Format("SELECT * FROM `tbl_2`; ");

                    using (MySqlCommand cmd = new MySqlCommand(sql))
                    {
                        cmd.Connection = con;
                        con.Open();

                        using (MySqlDataReader sdr = cmd.ExecuteReader())
                        {
                            while (sdr.Read())
                            {
                                var fruit = new Fruit(sdr["Un1"].ToString(),
                                    sdr["Un2"].ToString());
                                fruits.Add(fruit);
                            }
                        }
                        con.Close();
                    }
                }

                return fruits;
            }
        }

        [HttpGet]
        public ActionResult Index()
        {
            var personModel = new PersonModel();
            var fruitsRepo = new FruitsRepository();
            var fruits = fruitsRepo.GetAll();
            var fruitsSelecteListItems = fruits.Select(fruit => new SelectListItem
            {
                Text = fruit.Name,
                Value = fruit.Code
            }).ToList();
            personModel.Fruits = fruitsSelecteListItems;

            var cabinasRepo = new CabinaRepository();
            var cabinas = cabinasRepo.GetAll();
            var cabinasSelecteListItems = cabinas.Select(cabina => new SelectListItem
            {
                Text = cabina.NomeCabina,
                Value = cabina.CodiceCabina
            }).ToList();
            personModel.Nodo = cabinasSelecteListItems;

            return View(personModel);
        }

        public ActionResult About()
        {
            ViewBag.Message = "Your application description page.";
            return View();
        }

        public ActionResult Contact()
        {
            ViewBag.Message = "Your contact page.";
            return View();
        }
    }


    public class PersonModel
    {
        [Required]
        [Display(Name = "UOR")]
        public List<SelectListItem> Fruits { get; set; }

        [Required]
        [Display(Name = "Cabina")]
        public List<SelectListItem> Nodo { get; set; }

        [Required]
        [Display(Name = "Cabina")]
        public string SelectedCabina { get; set; }

        [Required]
        [Display(Name = "UOR")]
        public string SelectedFruitCode { get; set; }
    }