Build Mongo Query based on query parameters in url - node.js

Question

I want to build a query as per the value available in the query parameters of the URL. The sample URL is :-
http://localhost:3000/api/user?page=&status=&search&role_id=
So when the status is available, the where clause related to it should work, the same for search and role_id.
I have tried to built a query where pagination part along with search parameter is working perfectly. But when I pass/set the keys of
query string, the query shows no results.
The query I have build so far is something like this:-
let {page, search, status, role_id} = req.query;
role_id = role_id ? role_id : null;
status = status ? status : null;
const currentPage = parseInt(page) || 1;
const perPage = recordsPerPage;
const userData = await User.find({
$and: [
{
$or : [
{username:{'$regex' : search, '$options' : 'i'}},
{email:{'$regex' : search, '$options' : 'i'}}
]
},
{
$or : [
{status : status}
]
},
{
$or : [
{role_id : role_id}
]
},
{
email: { $ne: 'xxxxx#gmail.com' }
}
]
})
.sort({_id : -1})
.populate('role_id')
.skip((currentPage - 1) * perPage).limit(perPage);

Answer 1

Instead of trying to rely on $or and $and in your query, you can just conditionally add fields to your query. A mongoose query is just passed an object and can be built outside the function call.
This way you won't have to worry about edge cases such as a user with status null being returned whenever you leave out the status field from your query.
let {page, search, status, role_id} = req.query;
role_id = role_id ? role_id : null;
status = status ? status : null;
const currentPage = parseInt(page) || 1;
const perPage = recordsPerPage;
const query ={
email: { $ne: 'xxxxx#gmail.com' }
}
if (status) {
query.status = status
}
if (role_id) {
query.role_id = role_id
}
if (search) {
query.username = {'$regex' : search, '$options' : 'i'}
delete query.email
query['$and'] = [
{ email: {'$regex' : search, '$options' : 'i'}},
{ email: { $ne: 'xxxxx#gmail.com' } }
]
}
const userData = await User.find(query)
.sort({_id : -1})
.populate('role_id')
.skip((currentPage - 1) * perPage).limit(perPage);
As an aside, I think a query with a $regex and a $ne on the same field (email in your example) may be very slow once executed on a large collection.