MongoDB insertOne function not found - php

Question

I'm trying to use MONGODB in my project and I just started using it when it has this problem. I created another directory and ran the files with no problems whatsoever. What is wrong with this? I keep getting Fatal error: Uncaught Error: Call to undefined method MongoDB\Database::insertOne() error message.
This is my code to the class called Database which is producing the error.
<?php
namespace auth;
include_once dirname(__DIR__) . "/config.php";
class Database
{
public function __construct(
private readonly string $dbname,
){
$this->run();
}
private function run(): void
{
$collection = (new \MongoDB\Client)->{$this->dbname};
$insertOneResult = $collection->insertOne([
'username' => 'admin',
'email' => 'admin#example.com',
'name' => 'Admin User',
]);
printf("Inserted %d document(s)\n", $insertOneResult->getInsertedCount());
var_dump($insertOneResult->getInsertedId());
}
}
and my test.php file just contained some lines of code
include_once "./assets/php/config.php";
$database = new \auth\Database("test->users");
I definitely loaded the class MongoDB and my config.php includes the vendor file of composer's.
This is the error in full.
Fatal error: Uncaught Error: Call to undefined method MongoDB\Database::insertOne() in C:\xampp\htdocs\PP\assets\php\Classes\Database.php:18
Stack trace:
#0 C:\xampp\htdocs\PP\assets\php\Classes\Database.php(11): auth\Database->run()
#1 C:\xampp\htdocs\PP\test.php(15): auth\Database->__construct('test->users')
#2 {main}
thrown in C:\xampp\htdocs\PP\assets\php\Classes\Database.php on line 18
PHP Fatal error: Uncaught Error: Call to undefined method MongoDB\Database::insertOne() in C:\xampp\htdocs\PPa\assets\php\Classes\Database.php:18
Stack trace:
#0 C:\xampp\htdocs\PP\assets\php\Classes\Database.php(11): auth\Database->run()
#1 C:\xampp\htdocs\PP\test.php(15): auth\Database->__construct('test->users')
#2 {main}
thrown in C:\xampp\htdocs\PP\assets\php\Classes\Database.php on line 18
Process finished with exit code 255
The config.phpfile that I have included
include_once dirname(__DIR__, 2) . "/vendor/autoload.php";
include_once "autoload.php";
Thanks for any help.

Answer 1

Ah yes answer to my question, I'm just well not thinking properly at the time of writing the code. The `MongoDB\Collection" class accepts two arguments from the user and one internally set. The user provided argument is the database name and collection name. Doing it with (new \MongoDB\Client)->{$this->dbname} is wrong because it provides just the database string and not the collection name.
I resolved this issue by changing how the structure looks of the collection. md is just the alias for MongoDB class as I do not want to type such a long string everytime.
$collection = (new md\Client)->$db->$collection_name;
However, I have no idea how mongoDB uses the db and collection_name as magic constants as I have looked through the entire MongoDB\Client file and found there is no code stating those "magic constants"? I would appreciate if someone has an answer to this.