Grabbing data from MySQL using PHP realtime?

Use AJAX (I suggest using the jQuery library for this), and have your AJAX script (written in PHP) query the MySQL database.

You can use Socket.Io for more Speed ,efficiency and performance for Your Server

http://socket.io/

But you need Node.Js for that

You will have to use javascript. You can use setInterval(function, n) to fire your update calls every n milliseconds, and a library like jQuery to handle the ajax call and updating your page.

Download jQuery or link to a CDN hosted version of jQuery in your page. Then put something like this on your page:

setInterval(function(){
    // inside here, set any data that you need to send to the server
    var some_serialized_data = jQuery('form.my_form').serialize();

    // then fire off an ajax call
    jQuery.ajax({
        url: '/yourPhpScriptForUpdatingData.php',
        success: function(response){
            // put some javascript here to do something with the 
            // data that is returned with a successful ajax response,
            // as available in the 'response' param available, 
            // inside this function, for example:
            $('#my_html_element').html(response);
        },
        data: some_serialized_data
    });
}, 1000); 
// the '1000' above is the number of milliseconds to wait before running 
// the callback again: thus this script will call your server and update 
// the page every second.

Read the jquery docs under 'ajax' to understand the jQuery.ajax() call, and read about 'selection' and 'manipulation' if you don't understand how to update the html page with the results from your ajax call.

The other way to continuously update your page is to use a persistent connection, like web sockets (not currently supported across all the common browser platforms) or a comet-style server-push setup. Try googling comet and/or web sockets for more info, but I think the above method is going to be much easier to implement.