demo->whisky; $newReview = [ user_name => "Michael", date => new \MongoDB\BSON\UTCDateTime( new DateTimeImmutable("2017-02-02") ), note => "No peat, but fruity", rating => 1, ]; $whisky->updateOne( [ 'name' => 'Glenfiddich 15' ], [ '$push => [ 'notes' => $newReview ] ] ); ?>]]>