php如何创建数据库表

在PHP中，你可以使用MySQLi或PDO扩展来创建数据库表。以下是使用这两种方法的示例：

方法1：使用MySQLi

<?php// 连接到MySQL数据库$servername = "localhost";$username = "your_username";$password = "your_password";$dbname = "your_dbname";// 创建连接$conn = new mysqli($servername, $username, $password, $dbname);// 检查连接if ($conn->connect_error) {    die("连接失败: " . $conn->connect_error);}// 创建表的SQL语句$sql = "CREATE TABLE users (id INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY,username VARCHAR(30) NOT NULL,email VARCHAR(50),created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP)";// 执行SQL语句并检查是否成功if ($conn->query($sql) === TRUE) {    echo "表users创建成功";} else {    echo "创建表错误: " . $conn->error;}// 关闭连接$conn->close();?>

方法2：使用PDO

<?php// 连接到MySQL数据库$servername = "localhost";$username = "your_username";$password = "your_password";$dbname = "your_dbname";try {    // 创建连接    $conn = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);    // 设置 PDO 错误模式为异常    $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);    // 创建表的SQL语句    $sql = "CREATE TABLE users (    id INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY,    username VARCHAR(30) NOT NULL,    email VARCHAR(50),    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP    )";    // 执行SQL语句并检查是否成功    $conn->exec($sql);    echo "表users创建成功";} catch(PDOException $e) {    echo "创建表错误: " . $e->getMessage();}// 关闭连接$conn = null;?>

请注意，你需要将your_username、your_password和your_dbname替换为你自己的数据库凭据。