php捕获mysql错误

<?php
$host = 'localhost';
$user = 'username';
$password = 'password';
$dbname = 'database_name';

// 创建连接
$conn = new mysqli($host, $user, $password, $dbname);

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

// 执行SQL语句
$sql = "SELECT * FROM non_existent_table";
$result = $conn->query($sql);

// 检查查询结果
if (!$result) {
    echo "查询失败: " . $conn->error;
}

// 关闭连接
$conn->close();
?>

<?php
$host = 'localhost';
$user = 'username';
$password = 'password';
$dbname = 'database_name';

try {
    // 创建连接
    $conn = new PDO("mysql:host=$host;dbname=$dbname", $user, $password);
    $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

    // 执行SQL语句
    $sql = "SELECT * FROM non_existent_table";
    $result = $conn->query($sql);
} catch (PDOException $e) {
    echo "数据库连接失败: " . $e->getMessage();
}

// 关闭连接
$conn = null;
?>