OOP Database Connection

gistfile1.txt

<?php

class Student {
//    public function __construct() {
//        
//    }
    public function save_student_info($data){
        $host_name='localhost';
        $user_name='root';
        $password ='';
        $db_name='db_sudent_info';
        $connection = mysqli_connect($host_name,$user_name,$password,$db_name);
        if(!$connection){
            die('Connection Fail'.mysqli_errno($connection));
        }
        
        $sql = "INSERT INTO tbl_student (student_name,phone_number,email_address,address)VALUES('$data[student_name]','$data[phone_number]','$data[email_address]','$data[address]')";
        if(mysqli_query($connection, $sql)){
            $message="Student info save successfully";
            return $message;
        }else{
            die('Query problem'.mysqli_error($connection));
        }
    }
}