mysql注册登录

CREATE TABLE users (
    id INT AUTO_INCREMENT PRIMARY KEY,
    username VARCHAR(50) NOT NULL,
    password_hash CHAR(64) NOT NULL
);

INSERT INTO users (username, password_hash) VALUES ('user1', SHA2('password123', 256));

<?php
$username = $_POST['username'];
$password = $_POST['password'];

$conn = new mysqli('localhost', 'root', 'password', 'mydatabase');

if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}

$sql = "SELECT password_hash FROM users WHERE username = ?";
$stmt = $conn->prepare($sql);
$stmt->bind_param("s", $username);
$stmt->execute();
$stmt->bind_result($password_hash);
$stmt->fetch();

if (password_verify($password, $password_hash)) {
    echo "Login successful!";
} else {
    echo "Invalid username or password.";
}

$stmt->close();
$conn->close();
?>