调用非对象的成员函数 [英] call to a member function non-object

问题描述

我刚开始接触 PHP，我需要你的帮助.

I'm beginning with PHP and i need your help.

我尝试列出与 current_member 有相同兴趣的所有成员(我的意思是已连接的成员).

I create a try to list all members who has the same interest that the current_member( i mean the connected member ).

我是这样写的:

$current_members = params('current_member');
    $members_all = option('db')->query('SELECT * FROM members WHERE interest = $current_members["interest"] ORDER BY lastname, firstname')->fetchAll();

    set('members_all', $members_all);

当我进入我的页面时出现错误:致命错误:在非对象上调用成员函数 fetchAll()

When I go on my page I have the error : Fatal error: Call to a member function fetchAll() on a non-object

在我看来，我只是这样写:

And in my view I just write this :

        <h2 id="member-<?= $member['id'] ?>">

            <?= avatar_tag($member,'30x30') ?>

            <a href="<?=member_url_for($member)?>"><?=$member['firstname']?><small> <?= $member['lastname'] ?></small></a>

        </h2>

我不明白这个错误，任何人都可以帮助我吗?

I dont understand this error, anyone can help me ?

感谢您的帮助.

推荐答案

不要像您现在所做的那样将调用链接到 query() 和 fetchAll().这是不好的做法.永远不要假设您的查询有效，始终检查是否有效.

Do not chain calls to query() and fetchAll() like you are doing. That's bad practice. Never assume your query worked, always check to see if it did.

$db = option('db');
$query = $db->query('SELECT ...');
if($query === FALSE){
    print_r($db->errorInfo());
    die;
}
$members_all = $query->fetchAll();

_{(由于您正在调用 fetchAll()，我假设您使用的是 PDO(而不是 MySQLi))}

_{(Since you are calling fetchAll(), I assume you are using PDO (and not MySQLi))}

另外，不要尝试将变量连接到您的 SQL 查询中.(P.S. 你甚至没有这样做，你使用的是单引号，所以 $current_members["interest"] 没有被读取为变量)这只是要求进行 SQL 注入攻击.您要做的是使用准备好的语句.

Also, do not try to concatenate variables into your SQL query. (P.S. You're not even doing that, you are using single quotes, so $current_members["interest"] is not being read as a variable) That's just asking for an SQL injection attack. What you want to do is use prepared statements.

$db = option('db');
$query = $db->prepare('SELECT * FROM members WHERE interest = ? ORDER BY lastname, firstname');
$exec = $query->execute(array($current_members['interest']));
if($exec === FALSE){
    print_r($query->errorInfo());
    die;
}
$members_all = $query->fetchAll();

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