php连接mysql数据库练手

<?php
        $servername = "localhost";
        $username = "yosha";
        $password = "leon0924";
        $dbname = "test";

// 创建连接
        $conn = new mysqli($servername, $username, $password, $dbname);
// 检测连接
        if ($conn->connect_error) {
            die("连接失败: " . $conn->connect_error);
        }

        $sql = "SELECT * FROM student";
        $result = $conn->query($sql);

        if ($result->num_rows > 0) {
            // 输出每行数据
            
            while ($row = $result->fetch_assoc()) {

                echo "<br> 学号: " . $row["SID"] . " 姓名： " . $row["Name"] . " 年龄：" . $row["Age"];
                
            }
            
        } else {
            echo "0 个结果";
        }
        $conn->close();
        ?>