click button counter for all users PHP MySQL

I think it can be done with php and mysql but I’m not sure, so I ask you.

I have a site where every registered user has coins which are saved on the database.

I have a page with a button, and each user can click this button by spending 1 coin, and by doing this there will be a counter that will count how many coins have been spent (we can also think of them as clicks) but if a user has no coins he is redirected to “./ricarica.php”

any ideas?

Answer

I try to give you a minimal example (from our comment):

DB Structure:

Coin table:

ID-NOMECOIN-NUMEROTOTALE

User Table:

IDUSER-NOMEUSER-COINRIMASTI

Html:

<button id="checkcoin" value="<?php echo $row['id']?>">Controllo Coin</button>
//i suppose you have a query for select user id.

Js Call Ajax:

$(function () {
    $('#checkcoin').on('click', function () {
    var users = document.getElementById('checkcoin').value;
            $.ajax({
                url: "upd.php",
                type: "POST",
                data: {users : users},
                success: function(data){
                    //quello che vuoi che succeda.

                }        
           });


    });

PHP:

$iduser=$_POST['users'];
$query=$mysqli->prepare('SELECT * FROM users WHERE iduser=?');
$query->bind_param('i',$iduser);
$query->execute();
$store=$query->get_result();

while($res=$store->fetch_array()){
    $coinrimasti=$res['coinrimasti'];
}

$nuovocoin=$coinrimasti - 1;

if($nuovocoin=='20'){
    FunzioneResetta($iduser); // crei una funzione che resetta entrambi i contatori sia l'user che il totale
    echo 'hai vinto un premio';
}elseif($nuovocoin =='0' or $nuovocoin=='-1'){
    header(location:/ricarica.php);
}else{
    //fai l'update di entrambi i contatori uno in meno uno in più
}