PHP抛出无效PHP注意:正在尝试获取非对象的属性 - PHP throwing invalid PHP Notice: Trying to get property of non-object

PHP throwing invalid PHP Notice: Trying to get property of non-object

我收到一个错误，似乎发生了错误。

我已经在不同的类中得到了足够多的相同函数，但它似乎没有发生。我使用的功能是：

public function UserInfo($type, $value) {
    if($type == 'email') {
       $query = $this->db->prepare("SELECT * FROM `accounts` where `provider` = '1' AND `email` = :value AND `type` = 'client' LIMIT 1");
    } else {
       $query = $this->db->prepare("SELECT * FROM `accounts` where `provider` = '2 'AND `prov_id` = :value AND `type` = 'client' LIMIT 1");
    }
    $params = array(":value" => $value,);
    $query->execute($params);
    return $query->FetchObject();
}

我正试图通过获取数据

$clients->UserInfo("id", $uid)->email;

PHP返回值，所以很明显对象确实存在，但它仍然抛出

PHP Notice: Trying to get property of non-object in /Users/Luke/public_html/manage.php on line 30

我使用的语法有问题吗，还是PHP错误？

试试这个
这不会导致任何错误。

<?php
class DB {
    protected $db;
    public function __construct() {
        $this->db = PDO(
            'mysql:dbname=test;host=127.0.0.1;charset=utf8',
            'root', 
            ''
        );
        $this->db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    }
    public function UserInfo($type, $value) {
        if ($type == 'email') {
            $stmt = $this->db->prepare(
                "SELECT * FROM `accounts` where `provider` = '1' AND `email` = ? AND `type` = 'client' LIMIT 1"
            );
        } else {
            $stmt = $this->db->prepare(
                "SELECT * FROM `accounts` where `provider` = '2 'AND `prov_id` = ? AND `type` = 'client' LIMIT 1"
            );
        }
        $stmt->execute(array($value));
        $result = $stmt->fetchObject();
        if ($result === false) {
            throw new Exception('value not found');
        }
        return $result;
    }
}
try {
    $clients = new DB;
    echo $clients->UserInfo("id", $uid)->email;
} catch (Exception $e) {
    echo $e->getMessage();
}

我认为PHP在抱怨这一行：

$query->execute($params);

因为CCD_ 3不是在if-else子句之外声明的。另一种可能性是一个查询错误，因此$query是prepare()之后的False：http://php.net/manual/en/pdo.prepare.php

你能试试吗：

public function UserInfo($type, $value) {
    $sql_query = '';
    if($type == 'email') {
       $sql_query = "SELECT * FROM `accounts` where `provider` = '1' AND `email` = :value AND `type` = 'client' LIMIT 1";
    } else {
       $sql_query = "SELECT * FROM `accounts` where `provider` = '2 'AND `prov_id` = :value AND `type` = 'client' LIMIT 1";
    }
    $query = $this->db->prepare($sql_query);
    $params = array(":value" => $value,);
    if ($query === false) return 'False query';
    $query->execute($params);
    return $query->FetchObject();
}