php 防注入代码

<?php
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDB";

// 创建连接
$conn = new mysqli($servername, $username, $password, $dbname);

// 检查连接
if ($conn->connect_error) {
    die("连接失败: " . $conn->connect_error);
}

// 防注入的参数化查询
$stmt = $conn->prepare("SELECT * FROM users WHERE username = ? AND password = ?");
$stmt->bind_param("ss", $username, $password);

// 设置参数并执行
$username = $_POST['username'];
$password = $_POST['password'];
$stmt->execute();

$result = $stmt->get_result();

if ($result->num_rows > 0) {
    // 输出数据
    while($row = $result->fetch_assoc()) {
        echo "id: " . $row["id"]. " - Name: " . $row["username"]. "<br>";
    }
} else {
    echo "0 结果";
}

$stmt->close();
$conn->close();
?>