how to get number of documents which is created today with mongoose?

Question

how to get number of documents which is created today with mongoose? I'm using MEAN stack. I read Mongoose Api Docs but doesn't understand anything :/

Answer 1

By default there is no way.

Documents don't have creation date associated with them unless you explicitly store it in MongoDB.

In other words your Mongoose schema should have something like created field:

const blogSchema = new Schema({
  created: {type: Date, default: Date.now}
});

Then search for matching docs:

const now = new Date();
const today = new Date(now.getFullYear(), now.getMonth(), now.getDate());
doc.find({created: {$gte: today}}).exec(callback);

Answer 2

Supposing you have the date field createdAt in your schema and you would like to get the number of users registered today, you should create a two date object instances to use in your date range query, start and end dates.

Your start date object should hold the current date time hours at 00:00:00.000 (milliseconds precision) and set the hours for today's date to 23:59:59.999 to the end date variable:

var start = new Date();
start.setHours(0,0,0,0);

var end = new Date();
end.setHours(23,59,59,999);

Then pass the modified date objects as usual in your MongoDB aggregation pipeline in the $match operator:

var pipeline = [
    {
        "$match": {
            "createdAt": { "$gte": start, "$lt": end }
        }
    },
    {
        "$group": {
            "_id": null,
            "count": { "$sum": 1 }
        }
    }
];

Model.aggregate(pipeline, function (err, result){
    if (err) throw new Error();
    console.log(JSON.stringify(result));
});

If you are using the momentjs library, this can be done by using the startOf() and endOf() methods on the moment's current date object, passing the string 'day' as arguments:

var start = moment().startOf('day'); // set to 12:00 am today
var end = moment().endOf('day'); // set to 23:59 pm today