PHP를 사용하여 MySQL 테이블에 데이터를 삽입하는 방법은 무엇입니까?

<?php
$servername = "localhost";
$username = "root";
$password = "password";
$dbname = "database_name";

// 创建一个连接
$conn = new mysqli($servername, $username, $password, $dbname);

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

$sql = "INSERT INTO table_name (column1, column2, column3) VALUES (value1, value2, value3)";

if ($conn->query($sql) === TRUE) {
    echo "新记录已成功插入。";
} else {
    echo "插入数据时出错：" . $conn->error;
}
?>

$user_id = 1;
$first_name = "John";
$last_name = "Smith";

$sql = "INSERT INTO users (user_id, first_name, last_name) VALUES ($user_id, '$first_name', '$last_name')";

if ($conn->query($sql) === TRUE) {
    echo "新用户已成功插入。";
} else {
    echo "插入数据时出错：" . $conn->error;
}
?>