SImple Ajax Jquery with php & mysql query - php

Question

i look this tutorial
http://tutorialzine.com/2009/09/simple-ajax-website-jquery/
but i don't understand how to make this work with php file with sql, echo ""; etc
If someone can explain, i try everything and nothing appears
Thanks :)
var default_content = "";
$(document).ready(function () {
checkURL();
$('ul li a').click(function (e) {
checkURL(this.hash);
});
//filling in the default content
default_content = $('#pagesContent').html();
setInterval("checkURL()", 250);
});
var lasturl = "";
function checkURL(hash) {
if (!hash) hash = window.location.hash;
if (hash != lasturl) {
lasturl = hash;
// FIX - if we've used the history buttons to return to the homepage,
// fill the pageContent with the default_content
if (hash == "")
$('#pagesContent').html(default_content);
else
loadPage(hash);
}
}
function loadPage(url) {
url = url.replace('#page', '');
$('#loading').css('visibility', 'visible');
$.ajax({
type: "POST",
url: "load_page.php",
data: 'page=' + url,
dataType: "html",
success: function (data) {
if (parseInt(data) != 0) {
$('#pagesContent').html(data);
$('#loading').css('visibility', 'hidden');
}
}
});
}
load_page.php
<?php
if(!$_POST['page']) die("0");
$page = (int)$_POST['page'];
if(file_exists('pages/page_'.$page.'.php'))
echo file_get_contents('pages/page_'.$page.'.php');
else echo 'There is no such page!';
?>
demo.html
< a href="#page1">Page1< /a>
< a href="#page2">Page2< /a>
< a href="#page3">Page3< /a>
< a href="#page4">Page4< /a>
<div id="pageContent">
//loaded ajax page
</div>
in this scenario , link > index.html#page1 will load file 'pages/page_1.php'
but in main index.html just can load html code , not php syntax .
Can I use php command in this case ?

Answer 1

So it looks like the problem here is that in the tutorials example, they simply use an HTML file. For this, file_get_contents() will work fine. However if you want your server to parse PHP code before serving it to the user, you should use the include() function.
From the documentation :
The include statement includes and evaluates the specified file.
The file_get_contents() function behaves silghtly differently :
file_get_contents — Reads entire file into a string
It simply reads the contents of the file, the PHP code is not evaluated/executed/interpreted...