Question

我正在将当前未受保护的查询更新为参数化查询，以防止SQL注入。

我花了几个小时尝试对问题进行排序，但是找不到问题，非常感谢任何帮助。

之前（echo $ row ['storeID'];）在

之前有效

$storeName = mysqli_real_escape_string($conn,$_GET['store']); 
$query = "SELECT * FROM stores WHERE storeName = '$storeName'";
$results = mysqli_query($conn, $query);
$row = mysqli_fetch_assoc($results);

之后

$storeName = $_GET['store'];
$stmt = mysqli_prepare($conn, "SELECT * FROM stores WHERE storeName = ?");
mysqli_stmt_bind_param($stmt, "s", $storeName);
mysqli_stmt_execute($stmt);
$row = mysqli_stmt_fetch($stmt);

此回显应该起作用，但使用语句却不起作用

 echo $row['storeID'];

Answer 1

如果您查看mysqli_stmt_fetch的文档，则会看到以下说明：

从准备好的语句中获取结果到绑定变量中

因此，如果您想走这条路线，还需要同时mysqli_stmt_bind_result：

$storeName = $_GET['store'];
$stmt = mysqli_prepare($conn, "SELECT * FROM stores WHERE storeName = ?");
mysqli_stmt_bind_param($stmt, "s", $storeName);
mysqli_stmt_execute($stmt);
mysqli_stmt_bind_result($stmt, $col1, $col2, $col3,...);
while (mysqli_stmt_fetch($stmt)) {
    // do stuff with $col1, $col2, etc.
}

现在，在循环的每次迭代中，绑定结果变量将从结果集中获得值。

但是，我强烈建议您改用PDO，因为它不那么冗长：

$storeName = $_GET['store'];
$stmt = $db->prepare("SELECT * FROM stores WHERE storeName = ?");
$stmt->execute([$storeName]);
$rows = $stmt->fetchAll(PDO::FETCH_ASSOC);

// now you have a simple array with all your results
foreach ($rows as $row) {
    // do stuff with $row
}

Answer 2

在获取行之前，您缺少对mysqli_stmt_get_result的呼叫：

$storeName = $_GET['store'];
$stmt = mysqli_prepare($conn, "SELECT * FROM stores WHERE storeName = ?");
mysqli_stmt_bind_param($stmt, "s", $storeName);
mysqli_stmt_execute($stmt);
$result = mysqli_stmt_get_result($stmt);
$row = mysqli_fetch_assoc($result);

echo $row['id'];

PHP MySQLi参数化查询不起作用

2 个答案: