express mongoose pagination based on date (createdAt) - node.js

Question

Can anyone please suggest me how to implement pagination based on date? For example, users will push some data daily and they may want to see how many data records they've pushed on a certain day by paginating. They may not push the exact amount of data every day, so what is the most scalable way to implement this? Here is typical pagination that I implemented
router.get('/:page?', (req, res, next) => {
const perPage = 5;
let page = req.params.page || 1;
Upload.find({ user: req.user._id })
.populate('user text')
.skip((perPage * page) - perPage)
.limit(perPage)
.exec((err, uploads) => {
Upload.count().exec((err, count) => {
if (err) return next(err)
res.render('record', {
title: 'Records',
data: uploads,
current: page,
pages: Math.ceil(count / perPage)
});
})
})
});

Answer 1

well, so in this case we can go initially with the find query only.
later you can implement with aggregation.
so the idea is,
in each page we will show the data of each day, doesnot matter how many are there.
[surely not a good idea when you have a huge amount of data for that day or against your query]
here is what i have implemented for you:
router.get('/:page?', (req, res, next) => {
const page = req.params.page ? req.params.page : new Date().getDate();
const currentYear = new Date().getFullYear();
const currentMonth =new Date().getMonth();
Upload.find({
"createdAt": {
"$gte": new Date(currentYear, currentMonth, page),
"$lt": new Date(currentYear, currentMonth, page)}
})
.populate('user text')
.exec((err, uploads) => {
if (err) return next(err)
//uploads contains the result of date `page` of `currentMonth` month and year `currentYear`
res.render('record', {
title: 'Records',
data: uploads,
resultDay:page
});
})
});
few things to remember, in here, we cant use limit & skip as we are trying to query for a day.
so in this above if you pass the page param as 1 it will give the result of 1st day of the current month and current year.
in here we dont know how many page will be there, as because we dont know for which day how many docs are there in advance.
so, its expected in frontend you will show Next button and call this api. with the +1 value of current page value.
and accordingly you can show the previous button too.
to get count of all the docs of a sigle day you can pass the cindition part, which we are already using inside .find() in .count().
Hope this helps,
let me know if i've missed anything.