Updating documents
Update only updates the *first* document it finds by default.
demo->elephpants;
$c->drop();
$c->insert( [ '_id' => 'e42', 'name' => 'Kamubpo', 'age' => 17 ] );
$c->insert( [ '_id' => 'e43', 'name' => 'Denali', 'age' => 17 ] );
$c->update( [ 'age' => 17 ], [ '$inc' => [ 'age' => 1 ] ] );
var_dump( iterator_to_array( $c->find() ) );
?>]]>