PHP和Vue.js开发安全性最佳实践：防止代码插入攻击方法

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

try {
    $conn = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);
    $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

    $stmt = $conn->prepare("SELECT * FROM users WHERE username = :username");
    $stmt->bindParam(':username', $username);
    $stmt->execute();

    $result = $stmt->fetchAll(PDO::FETCH_ASSOC);
    // 处理查询结果
}
catch(PDOException $e) {
    echo "Error: " . $e->getMessage();
}
$conn = null;
?>

<?php
$name = $_POST['name'];
$name = htmlspecialchars($name);
// 使用过滤后的$name变量进行后续的操作
?>

<template>
  <div>
    <p v-html="safeHTML"></p>
  </div>
</template>

<script>
export default {
  data() {
    return {
      safeHTML: '<strong>安全的HTML代码</strong>'
    }
  }
}
</script>

<template>
  <div>
    <input v-model="name" @keydown.enter="submit">
    <p>{{ safeOutput }}</p>
  </div>
</template>

<script>
export default {
  data() {
    return {
      name: '',
      safeOutput: ''
    }
  },
  methods: {
    submit() {
      // 进行输入验证
      if (this.name.indexOf('<') >= 0) {
        // 非法输入
        alert('非法输入');
        return;
      }
      
      // 输出编码
      this.safeOutput = this.name.replace(/&/g, '&')
                                 .replace(/</g, '<')
                                 .replace(/>/g, '>');
    }
  }
}
</script>