MySQLi更新查询手动工作，但在脚本中不起作用

<?php
// 建立数据库连接
$servername = "localhost";
$username = "your_username";
$password = "your_password";
$dbname = "your_database";

$conn = new mysqli($servername, $username, $password, $dbname);

// 检查连接是否成功
if ($conn->connect_error) {
    die("连接数据库失败: " . $conn->connect_error);
}

// 执行更新查询
$sql = "UPDATE your_table SET column1 = 'new_value' WHERE condition = 'some_condition'";
if ($conn->query($sql) === TRUE) {
    echo "更新查询成功";
} else {
    echo "更新查询失败: " . $conn->error;
}

// 关闭数据库连接
$conn->close();
?>

<?php
// 建立数据库连接
$servername = "localhost";
$username = "your_username";
$password = "your_password";
$dbname = "your_database";

$conn = new mysqli($servername, $username, $password, $dbname);

// 检查连接是否成功
if ($conn->connect_error) {
    die("连接数据库失败: " . $conn->connect_error);
}

// 准备预处理语句
$stmt = $conn->prepare("UPDATE your_table SET column1 = ? WHERE condition = ?");
$stmt->bind_param("ss", $new_value, $condition);

// 设置参数并执行预处理语句
$new_value = "new_value";
$condition = "some_condition";
$stmt->execute();

// 检查更新是否成功
if ($stmt->affected_rows > 0) {
    echo "更新查询成功";
} else {
    echo "更新查询失败";
}

// 关闭预处理语句和数据库连接
$stmt->close();
$conn->close();
?>