get mongodb _id object after upsert with php

Question

is it possible to get the new/updated _id after the query? example code:

$key = array( \'something\' => \'unique\' );
$data = array( \'$inc\' => array(         


        

Answer 1

I ran into this issue and worked around it by querying back the _id after the upsert. I thought I'd add some of my findings in case they're useful to anyone who comes here searching for info.

When the upsert results in a new document being created in the collection, the returned object contains the _id (here's a print_r of an example):

Array

(

[updatedExisting] => 0

[upserted] => MongoId Object
    (
        [$id] => 506dc50614c11c6ebdbc39bc
    )

[n] => 1
[connectionId] => 275
[fsyncFiles] => 7
[err] => 
[ok] => 1
)

You can get the _id from this:

$id = (string)$obj['upserted'];

However, if the upsert resulted in an existing document being updated then the returned object does not contain _id.