Mongo - Fetch first created and last created document according to 'ts' (timestamp)

Is it possible to fetch first created and last created document according to 'ts' (timestamp) element of the doc开发者_JAVA技巧ument in single mongo query? If yes then please let me know how to query the mongo using php.

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You can't get them in one query, but you can do it in 2 queries.

db.collection.find().limit(1).sort([ts:-1])  --> Find the last timestampe
db.collection.find().limit(1).sort([ts:1])   --> Find the first timestamp 

or in PHP

$cursor = $collection->find()->sort(array('ts'=>-1))->limit(1);
$cursor = $collection=>find()->sort(array('ts'=>1))->limit(1);