在PHP中使用fetchAll返回多个数组

我正在尝试从数据库中检索多行。我遇到的问题是，每次使用此函数时，它都会替换我已尝试返回的所有其他行，并且只返回最后一行。如果有人知道更好的方法，或者知道如何真正做到这一点，请发表评论

新的张贴在这里，所以道歉，如果这是不正确的，在某些方面。谢谢

我的代码：

public function getPosts($id){
        global $pdo;

        $query = $pdo->prepare("SELECT * FROM friends WHERE f1 = ? OR f2 = ?");
        $query->bindValue(1, $id);
        $query->bindValue(2, $id);
        $query->execute();
        $res = $query->fetchAll();
            foreach($res as $user):
                if($user['f1'] == $id):
                    $query = $pdo->prepare("SELECT * FROM posts JOIN users ON posts.user_id = users.id WHERE user_id = ?");
                    $query->bindValue(1, $user['f2']);
                    $query->execute();
                else:
                    $query = $pdo->prepare("SELECT * FROM posts JOIN users ON posts.user_id = users.id WHERE user_id = ?");
                    $query->bindValue(1, $user['f1']);
                    $query->execute();
                endif;

                return $query->fetchAll(); //Trying to return arrays.
            endforeach;


}

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试试这样的。我不知道f1和f2是什么，所以我只是添加了它们作为占位符。我这里不使用bindValue。只使用

数组（$f1\u id，$f2\u id）

---

我建议将“posts”查询的结果添加到每个用户的“$res”数组中。然后返回“$res”数组，而不是仅返回特定用户的当前帖子

未测试代码：

public function getPosts($id){
        global $pdo;

        $query = $pdo->prepare("SELECT * FROM friends WHERE f1 = ? OR f2 = ?");
        $query->bindValue(1, $id);
        $query->bindValue(2, $id);
        $query->execute();
        $res = $query->fetchAll();
            foreach($res as &$user): // make a reference so i can modify it
                if($user['f1'] == $id):
                    $query = $pdo->prepare("SELECT * FROM posts JOIN users ON posts.user_id = users.id WHERE user_id = ?");
                    $query->bindValue(1, $user['f2']);
                    $query->execute();
                else:
                    $query = $pdo->prepare("SELECT * FROM posts JOIN users ON posts.user_id = users.id WHERE user_id = ?");
                    $query->bindValue(1, $user['f1']);
                    $query->execute();
                endif;

                $user['posts'] = $query->fetchAll(); // save the current users posts.
            endforeach;

            return $res; // all users and their posts.

}

---

我先前删除的关于剥离while循环的评论有点不完整和无用。所以我发布了一些代码。谢谢，非常感谢我所寻找的D@ivarpois

public function getPosts($id){
        global $pdo;

        $query = $pdo->prepare("SELECT * FROM friends WHERE f1 = ? OR f2 = ?");
        $query->bindValue(1, $id);
        $query->bindValue(2, $id);
        $query->execute();
        $res = $query->fetchAll();
            foreach($res as &$user): // make a reference so i can modify it
                if($user['f1'] == $id):
                    $query = $pdo->prepare("SELECT * FROM posts JOIN users ON posts.user_id = users.id WHERE user_id = ?");
                    $query->bindValue(1, $user['f2']);
                    $query->execute();
                else:
                    $query = $pdo->prepare("SELECT * FROM posts JOIN users ON posts.user_id = users.id WHERE user_id = ?");
                    $query->bindValue(1, $user['f1']);
                    $query->execute();
                endif;

                $user['posts'] = $query->fetchAll(); // save the current users posts.
            endforeach;

            return $res; // all users and their posts.

}