php连接数据库登录注册代码
时间: 2023-09-04 18:07:23 浏览: 42
以下是一个简单的 PHP 连接数据库、登录和注册的示例代码:
连接数据库:
```php
<?php
$host = "localhost"; // 数据库主机名
$username = "root"; // 数据库用户名
$password = ""; // 数据库密码
$dbname = "mydatabase"; // 数据库名
// 创建连接
$conn = mysqli_connect($host, $username, $password, $dbname);
// 检查连接是否成功
if (!$conn) {
die("Connection failed: " . mysqli_connect_error());
}
echo "Connected successfully";
?>
```
注册页面:
```php
<!DOCTYPE html>
<html>
<head>
<title>Registration</title>
</head>
<body>
<h2>Registration Form</h2>
<form action="register.php" method="post">
<label>Username:</label>
<input type="text" name="username" required><br>
<label>Email:</label>
<input type="email" name="email" required><br>
<label>Password:</label>
<input type="password" name="password" required><br>
<button type="submit" name="register">Register</button>
</form>
</body>
</html>
```
注册处理:
```php
<?php
// 连接数据库
$host = "localhost"; // 数据库主机名
$username = "root"; // 数据库用户名
$password = ""; // 数据库密码
$dbname = "mydatabase"; // 数据库名
$conn = mysqli_connect($host, $username, $password, $dbname);
// 检查连接是否成功
if (!$conn) {
die("Connection failed: " . mysqli_connect_error());
}
// 处理表单提交
if (isset($_POST['register'])) {
// 获取表单数据
$username = $_POST['username'];
$email = $_POST['email'];
$password = $_POST['password'];
// 将密码加密
$password = md5($password);
// 检查用户名是否已存在
$check_username_query = "SELECT * FROM users WHERE username='$username'";
$result = mysqli_query($conn, $check_username_query);
if (mysqli_num_rows($result) > 0) {
echo "Username already exists";
exit();
}
// 注册用户
$register_query = "INSERT INTO users (username, email, password) VALUES ('$username', '$email', '$password')";
mysqli_query($conn, $register_query);
echo "Registration successful";
}
?>
```
登录页面:
```php
<!DOCTYPE html>
<html>
<head>
<title>Login</title>
</head>
<body>
<h2>Login Form</h2>
<form action="login.php" method="post">
<label>Username:</label>
<input type="text" name="username" required><br>
<label>Password:</label>
<input type="password" name="password" required><br>
<button type="submit" name="login">Login</button>
</form>
</body>
</html>
```
登录处理:
```php
<?php
// 连接数据库
$host = "localhost"; // 数据库主机名
$username = "root"; // 数据库用户名
$password = ""; // 数据库密码
$dbname = "mydatabase"; // 数据库名
$conn = mysqli_connect($host, $username, $password, $dbname);
// 检查连接是否成功
if (!$conn) {
die("Connection failed: " . mysqli_connect_error());
}
// 处理表单提交
if (isset($_POST['login'])) {
// 获取表单数据
$username = $_POST['username'];
$password = $_POST['password'];
// 将密码加密
$password = md5($password);
// 查询用户
$login_query = "SELECT * FROM users WHERE username='$username' AND password='$password'";
$result = mysqli_query($conn, $login_query);
// 检查用户是否存在
if (mysqli_num_rows($result) > 0) {
echo "Login successful";
} else {
echo "Invalid username or password";
}
}
?>
```
注意:以上代码仅为示例,不足以用于真实项目中。在实际开发中,应该加强安全性和验证逻辑,例如使用预处理语句来防止 SQL 注入等安全问题。