Query the return of an Ajax

Question

I have a field select and need to query and load the result dynamically with Ajax. I currently have the following code (which does not appear to work or to be incomplete):

$('#formProd select').change(function(){

    $.ajax({
        type : 'POST',
        url  : 'index.php/home',
        data : {id : $('#formProd select option:selected').val()}
    });                     
});

How do I get this id to make me mine query?

I want to, by selecting an option from select, that on the same page he takes the value of select and make a query in my database to bring me the results.

Vide example.

When clicking on a category, I want you to click on a list of products.

Answer 1

If the problem is sending the ID of the option selected via Ajax, the code below should work smoothly:

$('#formProd select').change(function(){
    $.ajax({
        type: 'POST',
        url: 'index.php/home',
        data: { id: $(this).val() },
        //contentType: 'application/json; charset=utf-8',
        //dataType: 'json',
        success: function (data) {
            // utilizar o retorno
        }
    });
});

Note that to fill in the value of the ID you want to send you don’t need to access the value this way: $('#formProd select option:selected'), as you have already accessed the component via the "change" event, just use the $(this).val() to access the ID value of the selected option.

Answer 2

Your ajax does nothing when completing, but you must do an action that would fill your list with the returned elements in this way for example:

$.ajax({
    type : 'POST',
    url  : 'index.php/home',
    data : {id : $('#formProd select option:selected').val()}
}).done(function() {
  var len = data.id.length; //assumindo que vai retornar um Array.
  var List = []; //lista de elementos retornados
  for(var i=0; i < len; i++){ //percorre a lista de elementos retornados
    List.push("<li>"+data.id[i]+"</li>"); 
  }
  $('#linkList').html(List.join('')); //coloca as li's no ul com os elementos retornados.
});

About the Query you want to do, you can do something like:

$id = $_POST['id'];
if (is_numeric($id))
  $sql = 'SELECT * FROM sua_tabela WHERE id='.$id;

Note that I first checked whether the return of $_POST['id'] is number, so that there is no SQL Injection in your application.