php左连接mysql

<?php
// 数据库连接配置
$host = 'localhost';
$dbname = 'your_database';
$user = 'your_username';
$pass = 'your_password';

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

    // 左连接查询
    $sql = "SELECT users.name, orders.order_id, orders.order_date
            FROM users
            LEFT JOIN orders ON users.user_id = orders.user_id";

    $stmt = $pdo->query($sql);

    // 获取查询结果
    $results = $stmt->fetchAll(PDO::FETCH_ASSOC);

    // 输出结果
    foreach ($results as $row) {
        echo "Name: " . $row['name'] . ", Order ID: " . $row['order_id'] . ", Order Date: " . $row['order_date'] . "<br>";
    }
} catch (PDOException $e) {
    echo "Error: " . $e->getMessage();
}
?>