Using a Cursor to Get All of the Documents
Getting A Set of Documents With a Query
Tutorial
PHP Manual

## Setting Criteria for a Query

We can create a query to pass to the MongoCollection::find method to get a subset of the documents in our collection. For example, if we wanted to find the document for which the value of the "i" field is 71, we would do the following:

`<?php
$connection = new MongoClient();
$collection = $connection->database->collectionName;
$query = array( 'i' => 71 );
$cursor = $collection->find( $query );
while ( $cursor->hasNext() )
{
var_dump( $cursor->getNext() );
}
?>`

The above example will output:

    array(2) {
      ["_id"]=>
      object(MongoId)#6 (0) {
      }
      ["i"]=>
      int(71)
      ["_ns"]=>
      "testCollection"
    }