問題描述

我有一個使用魔法方法來存儲屬性的類.這是一個簡化的例子:

I have a class that uses magic methods to store properties. Here is a simplified example:

class Foo {
    protected $props;

    public function __construct(array $props = array()) {
        $this->props = $props;
    }

    public function __get($prop) {
        return $this->props[$prop];
    }

    public function __set($prop, $val) {
        $this->props[$prop] = $val;
    }
}

我試圖在執行后為 PDOStatement 的每個數據庫行實例化此類的對象，如下所示(不起作用):

I'm trying to instantiate objects of this class for each database row of a PDOStatement after it's executed, like this (doesn't work):

$st->setFetchMode(PDO::FETCH_CLASS, 'Foo');

foreach ($st as $row) {
    var_dump($row);
}

問題是 PDO::FETCH_CLASS 在我的類上設置屬性值時似乎沒有觸發神奇的 __set() 方法.

The problem is that PDO::FETCH_CLASS does not seem to trigger the magic __set() method on my class when it's setting property values.

如何使用 PDO 實現預期效果?

推薦答案

PDO 的默認行為是在調用構造函數之前設置屬性.在調用構造函數后設置獲取模式設置屬性時，在位掩碼中包含PDO::FETCH_PROPS_LATE，這將導致在未定義的屬性上調用__set魔術方法.

The default behavior of PDO is to set the properties before invoking the constructor. Include PDO::FETCH_PROPS_LATE in the bitmask when you set the fetch mode to set the properties after invoking the constructor, which will cause the __set magic method to be called on undefined properties.

$st->setFetchMode(PDO::FETCH_CLASS | PDO::FETCH_PROPS_LATE, 'Foo');

或者，創建一個實例并將其提取到其中(即將提取模式設置為 PDO::FETCH_INTO).

Alternatively, create an instance and fetch into it (i.e. set fetch mode to PDO::FETCH_INTO).

這篇關于使用 PDO::FETCH_CLASS 和魔術方法的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！