private function buildWheres()
    {
        $statement = '';

        foreach ($this->wheres as $where) {
            $statement = $where->build();
        }

        foreach ($this->andWheres as $andWhere) {
            $statement .= $andWhere->build();
        }

        foreach ($this->orWheres as $orWhere) {
            $statement .= $orWhere->build();
        }

        return $statement;
    }