SQL注入-此查询安全吗？

Question

我有一个页面，将不同的参数附加到用于查询的URL。

例如

http://www.example.com/search.php?category=Schools&country[]=Belgium&country[]=Czech+Republic

我的代码是这样的

if(isset($_GET['country'])){
$cties = "'" . implode("','", $_GET['country']) . "'";
}
else {
$cties = "'Albania','Andorra','Austria','Belarus','Belgium','Bosnia & Herzegovina','Bulgaria','Croatia','Czech Republic','Denmark','Estonia','Faroe Islands','Finland','France','Germany','Gibraltar','Great Britain','Greece','Hungary','Iceland','Ireland','Isle of Man','Italy','Latvia','Liechtenstein','Lithuania','Luxembourg','Macedonia','Malta','Moldova','Monaco','Montenegro','Netherlands','Norway','Poland','Portugal','Serbia','Romania','San Marino','Slovakia','Slovenia','Spain','Sweden','Switzerland','Ukraine','United Kingdom'";           
}
if(isset($_GET['category'])){
$cat = $_GET['category'];
}
else{
$cat = " ";
}

try{
// create the Prepared Statement

$stmt = $con->prepare("SELECT * FROM MyTable 
WHERE MyDate >= DATE(NOW()) 
AND (Category=:cat or '' = :cat) 
AND Country IN ($cties)
ORDER BY MyDate ASC");
$stmt->bindValue(':cat', $cat, PDO::PARAM_STR);
$stmt->execute();

我想知道此查询是否安全，如果不安全，我在做什么错。 提前致谢！

我终于明白了（感谢您的常识）：

if(isset($_GET['country'])){
$arr = $_GET['country']; 
}
else {          
$arr = array('Albania','Andorra','Austria','Belarus','Belgium','Bosnia & Herzegovina','Bulgaria','Croatia','Czech Republic','Denmark','Estonia','Faroe Islands','Finland','France','Germany','Gibraltar','Great Britain','Greece','Hungary','Iceland','Ireland','Isle of Man','Italy','Latvia','Liechtenstein','Lithuania','Luxembourg','Macedonia','Malta','Moldova','Monaco','Montenegro','Netherlands','Norway','Poland','Portugal','Serbia','Romania','San Marino','Slovakia','Slovenia','Spain','Sweden','Switzerland','Ukraine','United Kingdom');
}
if(isset($_GET['category'])){
$cat = $_GET['category'];
}
else{
$cat = " ";
}
// create the Prepared Statement
$in  = str_repeat('?,', count($arr) - 1) . '?';

$sql = "SELECT * FROM MyTable WHERE MyDate >= DATE(NOW()) 
    AND Country IN ($in)
    AND (Category=? or '' = ?) 
    ORDER BY MyDate ASC";
$stmt  = $con->prepare($sql);
$arr[] = $cat;  // adding category to array
$arr[] = $cat;  // we need it twice here
// finally - execute
$stmt->execute($arr);

Answer 1

是的，现在我明白了您的问题。 好吧，PDO对于这样的任务来说不太方便。 因此，首先，我将向您展示如何使用我自己的库来完成它：

$sql = "SELECT * FROM MyTable WHERE MyDate >= CURDATE() 
          AND (Category=?s or '' = ?s) 
          AND Country IN (?a)
          ORDER BY MyDate ASC"
$data = $db->getAll($sql, $cat, $cat, $_GET['country']);

但是我很清楚，大家都倾向于熟悉的方法。 好吧，让我们详细介绍一下丑陋的PDO

首先，目标是什么？ 目标是

1. 创建包含所有数据的占位符的查询。 我将坚持使用位置占位符，因为它们更易于实现。
2. 用必须绑定到占位符的所有变量创建一个数组

看来我们需要两个占位符来表示类别，并需要一些未知数来回城市。 好的，此行将创建一个占位符字符串：

$in   = str_repeat('?,', count($arr) - 1) . '?';

我们将插入查询中。

// $arr is array with all the vars to bind. at the moment it contains cities only
$arr = $_GET['country']; 
// creating string of ?s
$in  = str_repeat('?,', count($arr) - 1) . '?';
// building query
$sql = "SELECT * FROM MyTable WHERE MyDate >= DATE(NOW()) 
              AND Country IN ($in)
              AND (Category=? or '' = ?) 
              ORDER BY MyDate ASC";
$stm  = $db->prepare($sql);
$arr[] = $_GET['category'];  // adding category to array
$arr[] = $_GET['category'];  // we need it twice here
// finally - execute
$stm->execute($arr);
$data = $stm->fetchAll();

Answer 2

不，可以将SQL代码注入$_GET['country']参数中。 您不会在任何地方逃脱它。

请参见PHP PDO：是否可以将数组绑定到IN（）条件？