DB\SQL\Mapper::set PHP Метод

    function set($key, $val)
    {
        if (array_key_exists($key, $this->fields)) {
            $val = is_null($val) && $this->fields[$key]['nullable'] ? NULL : $this->db->value($this->fields[$key]['pdo_type'], $val);
            if ($this->fields[$key]['initial'] !== $val || $this->fields[$key]['default'] !== $val && is_null($val)) {
                $this->fields[$key]['changed'] = TRUE;
            }
            return $this->fields[$key]['value'] = $val;
        }
        // adjust result on existing expressions
        if (isset($this->adhoc[$key])) {
            $this->adhoc[$key]['value'] = $val;
        } else {
            // Parenthesize expression in case it's a subquery
            $this->adhoc[$key] = ['expr' => '(' . $val . ')', 'value' => NULL];
        }
        return $val;
    }