How to do pagination with a mongodb aggregate? - node.js

Question

While working on MongoDB.I have a problem with doing Pagination.When I'm trying to include Paginaiton with aggerate.I'm also trying to include facets in this.
My code: Just for doing search
app.get("/search", async(req, res) => {
try {
const text = req.query.text
let result = await collection.aggregate([
{
'$search': {
'text': {
'query': `${text}`,
'path': 'title'
}
}
}
]).toArray();
res.send(result)
} catch (error) {
console.error(error)
}
})
This works for both search as well as pagination.
like this, see, It doesn't require any optional request.query.page.
http://localhost:4000/search?text=mango
http://localhost:4000/search?text=mango?page=1
Now, I want to include the pagination with facets search as well...So,
server.get("/search", async(req, res) => {
try {
const key = req.query.key;
const value = req.query.value;
const text = req.query.text;
const page = req.query.page; //Page query create
let result = await collection.aggregate([
{
'$search': {
'text': {
'query': `${text}`,
'path': 'title'
}
}
},
{
'$match': {
[key]: `${value}`
}
}
]).toArray();
res.send(result)
} catch (error) {
console.error(error)
}
})
work for this: without no.of Pages
http://localhost:4000/search?text=Mango&key=Brand&value=rasna
Doesn't work for Pagination:
http://localhost:4000/search?text=Mango&key=Brand&value=rasna&page=2
where I'm wrong here? Do I need to create any additional function to make this works or Something else?

Answer 1

you can use both $skip and $limit aggregation pipelines to achieve this purpose. imagine that we want to have only 20 items per page. so our code looks like this:
server.get("/search", async(req, res) => {
try {
const key = req.query.key;
const value = req.query.value;
const text = req.query.text;
const page = req.query.page - 1; //We subtract one because we don't want skip first twenty items in first page
let result = await collection.aggregate([
{
'$search': {
'text': {
'query': `${text}`,
'path': 'title'
}
}
},
{
'$match': {
[key]: `${value}`
}
},
{ $skip: page * 20 },
{ $limit: 20 }
]).toArray();
res.send(result)
} catch (error) {
console.error(error)
}
})