Query to get last X minutes data with Mongodb

Question

I\'m beginning with mongodb, and I\'m trying to query my db that have this document format:

{ \"_id\" : ObjectId(\"520b8b3f8bd94741bf006033\"), \"value\" : 0         


        

Answer 1

You could also do below

  db.getCollection('collectionName').find({timestamp : {$gte: new Date().getTime()-(60*60*1000) } } )

The above query ll give you records of timestamp b/w now and 60 mins. if you like more then 60 mins - say 2 hrs you could change expression to (2*60*60*1000) for 30 mins (30*60*1000)

Answer 2

you can access the data of current timestamp from mongodb using nodejs

 const collection1 = dbo.collection('customers');
    var dateq = new Date();
      collection1.find({    "Timestamp" : { $gt: new Date(dateq.getTime() - 6000)}  
    }).toArray(function(err , docs){   
    console.log(docs);
    }

code end

Answer 3

Wow, thanks to @Alistair_Nelson I was able to get the data from n minutes ago, for example to get the last 18 minutes from ISODate("2013-08-14T14:00:00Z"):

db.mycol.find({timestamp:{$gt: new Date(ISODate("2013-08-14T14:00:00Z")-18*60000)}})

To get only the fields I need:

db.mycol.find({timestamp:{$gt: new Date(ISODate("2013-08-14T14:00:00Z")-18*60000)}},{value:1,timestamp:1, _id:0})

Answer 4

For the 18 minutes part, that's not really about MongoDB, but about JavaScript and what's available in the mongo shell:

query = {
    timestamp: { // 18 minutes ago (from now)
        $gt: new Date(ISODate().getTime() - 1000 * 60 * 18)
    }
}

Works in the mongo shell, but using Mongo drivers for other languages would be really different.

To "project" over a smaller schema with both values and timestamps:

projection = {
    _id: 0,
    value: 1,
    timestamp: 1,
}

Applying both:

db.mycol.find(query, projection).sort({timestamp: 1});

Well, that's still not a "set" since there might be duplicates. To get rid of them you can use the $group from the aggregation framework:

db.mycol.aggregate([
    {$match: query},
    {$group: {
        _id: {
            value: "$value",
            timestamp: "$timestamp",
        }
    }},
    {$project: {
        value: "$_id.value",
        timestamp: "$_id.timestamp",
    }},
    {$sort: {timestamp: 1}},
])