如何使用PHP从mongodb获取ID？

I'm trying to get the ID from mongodb to modify and delete user from a simple CRUD app with PHP and vue.js using axios

When I insert any user, I get this id.

{ "$oid": "5a8fd1ef1233610e40007667" }

I just need the ID that mongodb generate itself.

"5a8fd1ef1233610e40007667"

I'm using POST to get the ID and this is what I get when I use var_dump()

string(15) "[object Object]"

¿Any idea of how to get that ID? I've already tried several things, I hope you guys can help me

See the The MongoDB\BSON\ObjectId class.

In MongoDB, each document stored in a collection requires a unique _id field that acts as a primary key. If an inserted document omits the _id field, the driver automatically generates an ObjectId for the _id field.

specifically MongoDB\BSON\ObjectId::__toString, which returns the hexidecimal representation of the ObjectId. You can invoke __toString by casting the ObjectId to string, for example:

$stringID = (string)$objectID;

You do not need to create the ObjectID when you insert the record, for example (based on your comment)

$bulk = new MongoDB\Driver\BulkWrite();
$doc  = [ 'firstname' => $firstname, 'lastname' => $lastname ];
$bulk->insert($doc);
$result = $manager->executeBulkWrite('db.collection', $bulk);
var_dump($result);

The mongo driver will create and set the '_id' field, insert takes the array by reference and can alter it.