ElenaLelo

public function getNum()
    {
        $cur = date('ym');
        $num = 0;
        $c = $this->modx->newQuery('msOrder');
        $c->where(array('num:LIKE' => "{$cur}%"));
        $c->select('num');
        $c->sortby('id', 'DESC');
        $c->limit(1);
        if ($c->prepare() && $c->stmt->execute()) {
            $num = $c->stmt->fetchColumn();
        }
        if (empty($num)) {
            $num = '2864';
        }
        $num = explode('/', $num);
        $num = end($num)  + 1;
        return $num;
    }

if (empty($num)) {
            $num = date('dm') . '-000';
        }
        $num = explode('-', $num);
        $num = $cur . '-' . sprintf('%03d',($num[1] + 1));

$num = explode('/', $num);

[[!pdoPage?
	&element=`msCart`
	&limit=`1`
	 &tpl=`ваш чанк`
]]
[[!+page.nav]]