public function getAll($fields = null, $sqlQuery = false)
    {
        $sql = $this->buildQuery('select', $fields);
        if($sqlQuery === true) {
            return $this->getQuery();
        }
        $result = $this->executeQuery($sql);
        if($result->num_rows == 0) {
            return [];
        }
        while($row = $result->fetch_array(MYSQLI_ASSOC)) {
            $data[] = $row;
        }
        return $data;
    }