MySQL は、注文システムのユーザー ログインおよび登録機能を実装します。

CREATE TABLE user (
  id INT PRIMARY KEY AUTO_INCREMENT,
  username VARCHAR(30) NOT NULL,
  password VARCHAR(255) NOT NULL
);

<?php
// 获取用户输入的用户名和密码
$username = $_POST['username'];
$password = $_POST['password'];

// 连接MySQL数据库
$servername = "localhost";
$username = "root";
$password = "123456";
$dbname = "test";
$conn = new mysqli($servername, $username, $password, $dbname);

// 检查连接是否成功
if ($conn->connect_error) {
  die("连接失败: " . $conn->connect_error);
}

// 将用户名和密码插入到用户表中
$sql = "INSERT INTO user (username, password) VALUES ('$username', '$password')";

if ($conn->query($sql) === TRUE) {
  echo "注册成功";
} else {
  echo "注册失败: " . $conn->error;
}

$conn->close();
?>

<?php
// 获取用户输入的用户名和密码
$username = $_POST['username'];
$password = $_POST['password'];

// 连接MySQL数据库
$servername = "localhost";
$username = "root";
$password = "123456";
$dbname = "test";
$conn = new mysqli($servername, $username, $password, $dbname);

// 检查连接是否成功
if ($conn->connect_error) {
  die("连接失败: " . $conn->connect_error);
}

// 查询用户表，检查用户名和密码是否匹配
$sql = "SELECT * FROM user WHERE username='$username' AND password='$password'";
$result = $conn->query($sql);

// 检查查询结果是否为空
if ($result->num_rows > 0) {
  echo "登录成功";
} else {
  echo "登录失败";
}

$conn->close();
?>