Mongodb update: how to check if an update succeeds or fails?

Question

I think the title pretty much says it all.

I'm working with Mongodb in PHP using the pecl driver. My updates are working great, but I'd like to build some error checking into my funciton(s).

I've tried using lastError() in a pretty simple function:

function system_db_update_object($query, $values, $database, $collection) {
    $connection = new Mongo();
    $collection = $connection->$database->$collection;
    $connection->$database->resetError(); //Added for debugging
    $collection->update(
        $query,
        array('$set' => $values));
    //$errorArray = $connection->$database->lastError();
    var_dump($connection->$database->lastError());exit; // Var dump and /Exit/
}

But pretty much regardless of what I try to update (whether it exists or not) I get these same basic results:

array(4) {
  ["err"]=>
  NULL
  ["updatedExisting"]=>
  bool(true)
  ["n"]=>
  float(1)
  ["ok"]=>
  float(1)
}

Any help or direction would be greatly appreciated.

Answer 1

the "n" field is the number of documents that were updated, and "updatedExisting" tells whether any document was updated at all. you should be able to check those fields to see whether an update succeeded or not.