致命错误：未捕获的异常“异常”，消息“未提供”

Question

完全错误是这样的：致命错误：在第 12 行的 /var/www/html/pdo/Delete.php 中未捕获的异常“异常”和消息“未提供 id”+（！）异常：id 未在 / 中提供var/www/html/pdo/Delete.php 在第 12 行。我正在测试一个页面以调用一个删除函数，该函数删除与我在测试中给出的 id 匹配的行。它有效，它删除了具有该 ID 的行。但是给了我这个警告。这是我的代码：

<?php

    include_once("StudentManager.php");
    //assumption is that the following parameters are passed to this file   
    //$id to be deleted.

    //Tester
    StudentManager::Delete(6); // 6 was the id I deleted.

    extract($_REQUEST); 

    if(!isset($id)){
        throw new Exception("id not supplied");
        echo "Bad";  //It does not get to this.
    } //else {

        //echo StudentManager::Delete($id);

    //}



?>
//Delete(id) and returns the number of rows affected by the delete
    public static function Delete($id){
    $db = StudentManager::getPDOConnection();
    $sql = "DELETE FROM people WHERE id=".$id;

    $di = $db->prepare($sql);     

    $di->execute(array(":id"=>$id));       

    $affected_rows = $di->rowCount();                                    

    echo "<p>$affected_rows rows were Deleted.</p>";
    $db = null;
    return $affected_rows;

} //end of delete

Answer 1

throw new Exception("id not supplied");

此行引发导致您看到的致命错误的异常。

在这种情况下运行：

if(!isset($id)){

很明显，条件匹配，这意味着$id 变量没有设置。

另外，extract($_REQUEST) 是非常糟糕的做法。

简单范围示例：

function foo($a) {
    $a = 5;
    echo $a; //5
}
$a = 42;
echo $a; //42
foo($a); //will echo 5
echo $a; //Still 42. Different $a.