phpmysql参数绑定

<?php
try {
    $pdo = new PDO('mysql:host=localhost;dbname=test', 'username', 'password');
    $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

    $stmt = $pdo->prepare('SELECT * FROM users WHERE id = ?');
    $stmt->execute([$userId]);

    $user = $stmt->fetch(PDO::FETCH_ASSOC);
    echo "User name: " . htmlspecialchars($user['name']);
} catch (PDOException $e) {
    echo "Connection failed: " . $e->getMessage();
}
?>

<?php
try {
    $pdo = new PDO('mysql:host=localhost;dbname=test', 'username', 'password');
    $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

    $stmt = $pdo->prepare('SELECT * FROM users WHERE id = :id');
    $stmt->bindParam(':id', $userId, PDO::PARAM_INT);
    $stmt->execute();

    $user = $stmt->fetch(PDO::FETCH_ASSOC);
    echo "User name: " . htmlspecialchars($user['name']);
} catch (PDOException $e) {
    echo "Connection failed: " . $e->getMessage();
}
?>

$stmt->execute([$userId]); // 确保$userId是一个有效的值

echo "User name: " . htmlspecialchars($user['name']);