public function update(SQLStatement $update): string
    {
        $sql = 'UPDATE ';
        $sql .= $this->handleTables($update->getTables());
        $sql .= $this->handleJoins($update->getJoins());
        $sql .= $this->handleSetColumns($update->getColumns());
        $sql .= $this->handleWheres($update->getWheres());

        return $sql;
    }