用PHP/MySql脚本创建和更新用户表

<?php
// 连接到MySQL数据库
$servername = "localhost";
$username = "root";
$password = "password";
$dbname = "mydatabase";
$conn = new mysqli($servername, $username, $password, $dbname);
if ($conn->connect_error) {
    die("连接失败: " . $conn->connect_error);
}

// 创建用户表
$sql = "CREATE TABLE users (
    id INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY,
    username VARCHAR(30) NOT NULL,
    email VARCHAR(50) NOT NULL,
    password VARCHAR(255) NOT NULL
)";
if ($conn->query($sql) === TRUE) {
    echo "用户表创建成功";
} else {
    echo "创建用户表时出错: " . $conn->error;
}

$conn->close();
?>

<?php
// 连接到MySQL数据库
$servername = "localhost";
$username = "root";
$password = "password";
$dbname = "mydatabase";
$conn = new mysqli($servername, $username, $password, $dbname);
if ($conn->connect_error) {
    die("连接失败: " . $conn->connect_error);
}

// 更新用户表，添加新的列
$sql = "ALTER TABLE users ADD COLUMN age INT(3)";
if ($conn->query($sql) === TRUE) {
    echo "用户表更新成功";
} else {
    echo "更新用户表时出错: " . $conn->error;
}

$conn->close();
?>