validate contact us page 2021 php coding

1<?php
2$conn = mysqli_connect("localhost", "root", "test", "blog_samples") or die("Connection Error: " . mysqli_error($conn));
3mysqli_query($conn, "INSERT INTO tblcontact (user_name, user_email,subject,content) VALUES ('" . $name. "', '" . $email. "','" . $subject. "','" . $content. "')");
4$insert_id = mysqli_insert_id($conn);
5if(!empty($insert_id)) {
6$message = "Your contact information is saved successfully";
7?>
8

1CREATE TABLE `tblcontact` (
2  `contact_id` int(11) NOT NULL,
3  `user_name` varchar(100) NOT NULL,
4  `user_email` varchar(255) NOT NULL,
5  `subject` varchar(255) NOT NULL,
6  `content` text NOT NULL
7) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;
8