Question

I am trying to find expired session by running query on this collection

{
  "_id" : ObjectId("4e4e88b81144e5a658000000"),
  "__meta" : { 
    "id" : "3a72c90f8455e2fd4b8a05ffa04b870a8672f1a9",
    "expiration" : "3600",
    "timestamp" : 1313769656 
  }
}

the query

db.sessions.find({$where: function(){
  return (this.__meta.timestamp + this.__meta.expiration) <= Math.round(new Date().getTime()/1000);
}})

I am expecting to get the collection, but I get an empty result.

Answer 1

You can use the javascript parseInt() function to convert a string to an integer. Be sure to use it in the form parseInt(my_string, 10), where the second argument is the integer base; its default behavior is to sense the base automatically, so strings like “0400” are interpreted as octal, not decimal.