php mysql怎么交互

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

// 创建连接
$conn = mysqli_connect($host, $user, $pass, $dbname);

// 检查连接
if (!$conn) {
    die('Connection failed: ' . mysqli_connect_error());
}

// 执行查询
$sql = 'SELECT id, name FROM users LIMIT 5';
$result = mysqli_query($conn, $sql);

// 处理结果
if (mysqli_num_rows($result) > 0) {
    while($row = mysqli_fetch_assoc($result)) {
        echo 'ID: ' . $row['id'] . ' - Name: ' . $row['name'] . '<br>';
    }
} else {
    echo '0 results';
}

// 关闭连接
mysqli_close($conn);
?>

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

try {
    // 创建PDO实例
    $pdo = new PDO("mysql:host=$host;dbname=$dbname;charset=utf8", $user, $pass);

    // 设置错误模式
    $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

    // 执行查询
    $sql = 'SELECT id, name FROM users LIMIT 5';
    $stmt = $pdo->query($sql);

    // 处理结果
    while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
        echo 'ID: ' . $row['id'] . ' - Name: ' . $row['name'] . '<br>';
    }
} catch(PDOException $e) {
    echo 'Connection failed: ' . $e->getMessage();
}

// 关闭连接
$pdo = null;
?>