Implementing mongodb pagination along with match query? - node.js

Question

I have user document as this
users = [
{
_id:'',
name:'jay',
email:'jay#gmail.com',
role: 'actor',
status: true // isActive
},
{
_id:'',
name:'ram',
email:'ram123#gmail.com',
role: 'electrician',
status: false // isActive
},
...... so on
]
I want to apply pagination and also some filters to retrieve data
filter = {
role: 'actor',
order: -1 //descending sort,
sortOn: 'name' // apply sort on name field
search: 'ja', // match the string starting with 'ja',
status: true,
size:25,
page: 1 // means documents from 1-25, page2 means 26-50
}
How can this be achieved?
I am using mongoose as well.

Answer 1

Using your filter object you can do something like this:
Use these steps to ensure a good pagination:
Sort by any value (to ensure not get random positions)
Skip by the number of pages
Limit by the number of elements into page
So, the query will be something like (not tested but you can see the idea):
const elementsPerPage = filter.size
const nSkip = elementsPerPage * filter.page
const sort = {[filter.sortOn]:filter.order}
YourModel.find({/*yourquery*/})
.limit(elementsPerPage)
.skip(nSkip)
.sort(sort)
Also, you can use filter values into your query, something like:
YourModel.find({
role: filter.role,
status:filter.status,
name:{ $regex: filter.search}
})
This query is like this example.
Also, is not defined what calues do you want to use, the condition etc, so, with this, you can use if/else to add or not values into query.
For example:
var query = {}
if(filter.search){
query.name = {$regex: filter.search}
}
So all together can be:
const elementsPerPage = filter.size
const nSkip = elementsPerPage * filter.page
const sort = {[filter.sortOn]:filter.order}
var query = {}
if(filter.search){
query.name = {$regex: filter.search}
}
if(filter.role){
query.role = filter.role
}
if(filter.status){
query.status = filter.status
}
YourModel.find(query)
.limit(elementsPerPage)
.skip(nSkip)
.sort(sort)
Note that this has not been tested, but as I've said before you can see the idea with this example.