Ajax get value from php - php

Question

Ajax
$(document).ready(function(){
$("#diklat").change(function(){
var diklat = $("#diklat").val();
$.ajax({
url: "function.php",
data: {'action': 'diklat'},
cache: false,
success: function(msg){
$("#angkatan").html(msg);
}
});
});
PHP
$get_action = $_GET['action'];
if($get_action=='diklat'){
$diklat = $_GET['diklat'];
$angkatan = mysql_query("SELECT id,name FROM batches WHERE IdMasterDiklat='$diklat' order by id");
echo "<option>-- Pilih Angkatan --</option>";
while($p = mysql_fetch_array($angkatan)){
echo "<option value=\"".$p['id']."\">".$p['name']."</option>\n";
}
}
The value didnt include in my ajax, ajax only read echo. how to get that value

Answer 1

You have written data: {'action': 'diklat'} but it should dilkat without quotes as its variable so in php you will get value in $_GET['action'].
Ajax
$(document).ready(function(){
$("#diklat").change(function(){
var diklat = $("#diklat").val();
$.ajax({
url: "function.php",
data: {'action': diklat},
cache: false,
success: function(msg){
$("#angkatan").html(msg);
}
});
});
PHP
if($_GET['action'] == 'diklat'){
$diklat = $_GET['action'];
$angkatan = mysql_query("SELECT id,name FROM batches WHERE IdMasterDiklat='$diklat' order by id");
echo "<option>-- Pilih Angkatan --</option>";
while($p = mysql_fetch_array($angkatan)){
echo "<option value=\"".$p['id']."\">".$p['name']."</option>\n";
}
}

Answer 2

You should pass 2 variables, one action and another id (diklat)
Ajax:
$(document).ready(function(){
$("#diklat").on('change', function(){
var diklat = $("#diklat").val();
$.ajax({
type: "POST",
url: "function.php",
data: {'action': 'diklat', 'diklat':diklat},
cache: false,
success: function(msg){
$("#angkatan").html(msg);
}
});
});
PHP
$action = isset($_POST['action']) ? $_POST['action'] : '';
if ($action == 'diklat')
{
$diklat = isset($_POST['diklat']) ? $_POST['diklat'] : '';
$angkatan = mysql_query("SELECT id, name FROM batches WHERE IdMasterDiklat='$diklat' order by id");
echo "<option>-- Pilih Angkatan --</option>";
while($p = mysql_fetch_array($angkatan))
{
echo "<option value=\"".$p['id']."\">".$p['name']."</option>\n";
}
}

Answer 3

Two things:
For a GET request, to ask a PHP server, data should be URL-encoded (as you see here, query string is just appended to the URL...) So tell 'data' : '?action=diklat' ...
EDIT : Jquery automatically converts object to Url-encoded query string... So It work with array ! I'm confusing with angular's $http...
And also, the parameter will be in $_GET['action'] (because action is parameter name, and diklat the value... So PHP convert query string to associative array, with parameters names as keysn and values as values...