正确插入PhP和MySQL用户数据

INSERT INTO users (username, email, password) VALUES ('John', 'john@example.com', 'password123');

<?php
// 建立与MySQL数据库的连接
$servername = "数据库主机名";
$username = "数据库用户名";
$password = "数据库密码";
$dbname = "数据库名";

$conn = mysqli_connect($servername, $username, $password, $dbname);

// 检查连接是否成功
if (!$conn) {
    die("数据库连接失败: " . mysqli_connect_error());
}

// 编写SQL语句
$sql = "INSERT INTO users (username, email, password) VALUES ('John', 'john@example.com', 'password123')";

// 执行SQL语句
if (mysqli_query($conn, $sql)) {
    $affected_rows = mysqli_affected_rows($conn);
    echo "成功插入 " . $affected_rows . " 行数据";
} else {
    echo "插入数据失败: " . mysqli_error($conn);
}

// 关闭数据库连接
mysqli_close($conn);
?>