mysql无法输入参数

-- 错误的SQL语句示例
SELECT * FROM users WHERE id = '1';

-- 正确的SQL语句示例
SELECT * FROM users WHERE id = 1;

-- 错误的参数类型示例
SELECT * FROM users WHERE id = 'one';

-- 正确的参数类型示例
SELECT * FROM users WHERE id = 1;

// 错误的参数化查询示例
$stmt = $pdo->query("SELECT * FROM users WHERE id = '1'");

// 正确的参数化查询示例
$stmt = $pdo->prepare("SELECT * FROM users WHERE id = :id");
$stmt->bindParam(':id', $id);
$stmt->execute();

// 检查数据库连接示例
try {
    $pdo = new PDO('mysql:host=localhost;dbname=test', $user, $pass);
} catch (PDOException $e) {
    echo "Connection failed: " . $e->getMessage();
}

-- 检查用户权限示例
SHOW GRANTS FOR 'username'@'localhost';