public static function count($where = null): int
    {
        $select = static::select();

        if ($where !== null) {
            if ($where instanceof Where) {
                $select->field('COUNT(*)', 'total');
                $select->where(clone $where);

            } else if (is_array($where)) {
                $select->field('COUNT(*)', 'total');
                foreach ($where as $field => $value) {
                    $select->where($field, $value);
                }

            } else if (!is_array(static::$primaryKey) && (is_numeric($where) || is_string($where))) {
                $select->field('COUNT(' . static::$primaryKey . ')', 'total');
                $select->where(static::$primaryKey, $where);

            }
        } else {
            $pk = is_string(static::$primaryKey) ? static::$primaryKey : '*';
            $select->field('COUNT(' . $pk . ')', 'total');
        }

        $results = $select->fetchAll();

        if (isset($results[0])) {
            $r = $results[0];
            if (array_key_exists('total', $r)) {
                return (int)$r['total'];
            } else {
                return 0;
            }
        } else {
            return 0;
        }
    }