Doesn't show created mongodb

Question

I am doing project using mongodb. so here I wrote separate functions to create db. this is my code

            $conn = new \MongoClient('mongodb://example.com:27017', array("connect" => TRUE));
            $exist_dbs = $conn->listDBs();

            foreach ($exist_dbs["databases"] as $databse) {
                if ($databse['name'] == $db_name) {
                    $is_exist = true;
                }
            }

            if (!$is_exist) {
                $db = new \MongoDB($conn, $db_name);
                $status = true;
                $msg = 'database successfully created';

            } else {
                $status = false;
                $msg = 'database already exist';
            }
            $conn->close();

but after create db it didn't show. but if I add record to that like this,

            $conn = new \MongoClient('mongodb://example.com:27017', array("connect" => TRUE));
            $exist_dbs = $conn->listDBs();

            foreach ($exist_dbs["databases"] as $databse) {
                if ($databse['name'] == $db_name) {
                    $is_exist = true;
                }
            }

            if (!$is_exist) {
                $db = new \MongoDB($conn, $db_name);
                $status = true;
                $msg = 'database successfully created';
                //new code
                $collection = new \MongoCollection($db, 'users');
                $obj = array("name" => "Madawa", "age" => "34");
                $collection->insert($obj);
            } else {
                $status = false;
                $msg = 'database already exist';
            }
            $conn->close();

it shows the database. what is the reason please help me.

Answer 1

When you say

$db = new \MongoDB($conn, $db_name);

You aren't creating a database, you are creating an object that can access a database. It doesn't mean the database does exist or that it makes it, just that you now have an object capable of accessing it. So you've basically said "Make me a database object to handle my calls and I'd like to select $db_name" but that is all that has happened. The database doesn't exist until you put something into it or perform some action on it.