Php 如何通过类函数显示获取的数据库数据

我是OOP新手，需要一些帮助我有一些代码可以从数据库中选择和获取数据，但我不知道如何显示获取的数据

/**
 * Connect to mysql database
 *
 * @return bool;
 */
public function Connect() {
    $settings = database_settings();
    $connect = new mysqli($settings->host, $settings->user, $settings->password, $settings->database);
    if (!$connect->connect_errno) {
        return $connect;
    } else {
        return false;
    }
}
/**
 * Prepare a mysqli query
 *
 * @return bool;
 */
public function statement($query) {
    if (!empty($query)) {
        $this->query = $query;
        return true;
    }
    return false;
}

/**
 * Execute a mysqli query and store result in memory
 *
 * @return bool;
 */
public function execute() {
    $this->database = $this->Connect();
    if (isset($this->query) && !empty($this->query)) {
        $this->database->set_charset("utf8");
        $this->exe = $this->database->query($this->query);
        if (!isset($this->exe)) {
            throw new DatabaseException("{$this->database->error} \n {$this->query} ");
        }
        if (isset($this->database->insert_id)) {
            $this->last_id = $this->database->insert_id;
        }
        unset($this->query);
        $this->database->close();
        return true;
    }
    return false;
}

/**
 * Prepare a query to select data from database
 *
 * @params = array();
 *           $params['from'] = names of table
 *           $params['params'] = names of columns which you want to select
 *           $params['wheres'] =  specify a selection criteria to get required records
 *
 * @return bool;
 */
public function select($params, $multi = '') {
    if (is_array($params)) {
        if (!isset($params['params'])) {
            $parameters = '*';
        } else {
            $parameters = implode(', ', $params['params']);
        }
        $order_by = '';
        if (!empty($params['order_by'])) {
            $order_by = "ORDER by {$params['order_by']}";
        }
        $where = '';
        if (isset($params['wheres']) && is_array($params['wheres'])) {
            $where = implode(' ', $params['wheres']);
        }
        $wheres = '';
        if (!empty($params['wheres'])) {
            $wheres = "WHERE({$where})";
        }
        $limit = '';
        if (!empty($params['limit'])){
            $limit = "LIMIT {$params['limit']}";
        }
        $query = "SELECT {$parameters} FROM `{$params['from']}` {$wheres} {$order_by} {$limit};";
        $this->statement($query);
        if ($this->execute()) {
            return $this->fetch($multi);
        }
    }
    return false;
}

/**
 * Fetch the data from memory that is stored during execution;
 *
 * @params = $data = (ture if you want to fetch all data , or flase if only one row)
 *
 * @return bool;
 */
public function fetch($data = false) {
    if (isset($this->exe)) {
        if ($data !== true) {
            if ($fetch = $this->exe) {
                return arrayObject($fetch->fetch_assoc());
            }
        }
        if ($data === true) {
            if ($fetch = $this->exe) {
                while ($all = $fetch->fetch_assoc()) {
                    $alldata[] = arrayObject($all);
                }
            }
            if (isset($alldata) && !empty($alldata)) {
                return arrayObject($alldata);
            }
        }
    }
    return false;
}

然后我选择了数据，但无法显示：

$params['from'] = 'category';
$params['order_by']= 'id';
$params['wheres'] = 'active="1"';
$params['limit']= '1';
$connect->select($params);

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与显示任何变量的方式相同？我不确定这里的问题是什么，但听起来它与这个数据库类没有任何关系。或者问题是您无法从内存中获取存储的数据？我获取数据，但不知道如何从功能中访问它们