(PECL mongo >=0.9.0)
MongoCollection::count — Counts the number of documents in this collection
Array or object with fields to match.
Returns the number of documents matching the query.
Exemplo #1 MongoCollection::count() example
<?php
$collection->insert(array('x'=>1));
$collection->insert(array('x'=>2));
$collection->insert(array('x'=>3));
var_dump($collection->count());
var_dump($collection->count(array('x'=>1)));
?>
O exemplo acima irá imprimir algo similar a:
int(3) int(1)