Posto anche un pò di codice per capirci:
Codice PHP:
$db =& new Db("localhost", "user", "pasw", "db");
$db->SetQueryValue("USE $db->dbName");
$db->SetQueryValue("BEGIN");
$query = "SELECT amount FROM stack_level WHERE cod = 1060";
$db->ExecQuery($query);
while (list($value) = $db->GetQueryValue()) {
if ($value > 0) {
echo "<html><head></head><body>";
echo "Disponibilità magazzino:
html_form();
if (isset($_POST['q'])) {
$q =& trim($_POST['q']);
$query = "UPDATE stack_level SET amount = (amount -'$q')
WHERE cod = 1060";
$db->SetQueryValue($query);
$db->SetQueryValue("COMMIT");
$value
";
}
}else {
$db->SetQueryValue("ROLLBACK");
echo "[b]Non Disponibile[/b]";
}
}
echo "</body></html>";