An example of an express route that uses query-to-mongo

q2m-example.js

var express = require('express')
var mongoskin = require('mongoskin')
var ObjectID = require('mongodb').ObjectID
var query2m = require('query-to-mongo')

// attach db to the router
var db = mongoskin.db('mongodb://localhost:27017/mydb', {safe: true})
var router = express.Router()
router.db = db
router.use(function (req, res, next) {
    req.db = router.db
    next()
})

function normalizeId(id) {
    if (ObjectID.isValid(id)) return new ObjectID(id)
    return id;
}

router.param('id', function (req, res, next, id) {
    req.idMatch = { _id: normalizeId(id) }
    next()
})

// get an object from the collection
router.get('/mycollection/:id', function (req, res, next) {
    var collection = req.db.collection('my')
    collection.findOne(new ObjectId(req.idMatch), function (e, result) {
        if (e) return next(e)
        if (!result) res.status(404) // Not Found
        res.locals.json = result
        next()
    })
})

// query objects in the collection
router.get('/mycollection', function (req, res, next) {
    var query = query2m(req.query, { ignore: 'envelope' })
    var collection = req.db.collection('my')

    collection.count(query.criteria, function (e, count) {
        var links
        if (e) return next(e)
        res.append('X-Total-Count', count)
        var fullUrl = req.protocol + '://' + req.get('host') + req.originalUrl
        links = query.links(fullUrl, count)
        if (links) res.links(links)
        collection.find(query.criteria, query.options).toArray(function (e, results) {
            if (e) return next(e)
            res.locals.json = results
            next()
        })
    })
})

// attach the route to the app and serve
var app = express()
app.use('/api/v1', router)
var server = app.listen(3000, function () {
    console.log('Listening on Port', server.address().port)
})