Work with Mongoose

[Damien2k9]

Hi leodinas

I'm having trouble working with Mongoose and its package. I wanted an example of how I can sort by various categories.

my code:

router.get('/products/:page', function(req, res, next){
    const perPage = 15;
    var page = req.params.page || 1;
    var sortBy = req.query.sortBy || 'name';
    var order = req.query.order || 'asc';

    Product
        .find({})
        .sort({name: 'asc'})
        .skip((perPage * page) - perPage)
        .limit(perPage)
        .exec(function(err, products){
            Product.countDocuments().exec(function(err, count){
                if(err) return next(err)
                res.render('products', {
                    products: products,
                    current: page,
                    pages: Math.ceil(count / perPage)
                });
                //console.log("Sort: " + sortBy + " Order: " + order);
            });
        });
});

In the code I created 2 variables to try to sort but it is not working and I would like to use your package, but I don't know how to implement it in my code, can you help me?

Thanks

[Damien2k9]

Hi again

Now I recived this error when I start the server....

import { MongooseQueryParser } from 'mongoose-query-parser';
       ^

SyntaxError: Unexpected token {
    at Module._compile (internal/modules/cjs/loader.js:720:22)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:788:10)
    at Module.load (internal/modules/cjs/loader.js:643:32)
    at Function.Module._load (internal/modules/cjs/loader.js:556:12)
    at Module.require (internal/modules/cjs/loader.js:683:19)
    at require (internal/modules/cjs/helpers.js:16:16)
    at Object.<anonymous> (C:\xampp\htdocs\acma\server.js:20:24)
    at Module._compile (internal/modules/cjs/loader.js:777:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:788:10)
    at Module.load (internal/modules/cjs/loader.js:643:32)
    at Function.Module._load (internal/modules/cjs/loader.js:556:12)
    at Function.Module.runMain (internal/modules/cjs/loader.js:840:10)
    at internal/main/run_main_module.js:17:11

My Code:

import { MongooseQueryParser } from 'mongoose-query-parser';

const parser = new MongooseQueryParser();

router.get('/products/:page', function(req, res, next){
    const perPage = 15;
    var page = req.params.page || 1;

    parser.parse('sort=name');

    Product
        .find({})
        .sort(parser)
        .skip((perPage * page) - perPage)
        .limit(perPage)
        .exec(function(err, products){
            Product.countDocuments().exec(function(err, count){
                if(err) return next(err)
                res.render('products', {
                    products: products,
                    current: page,
                    pages: Math.ceil(count / perPage)
                });
                //console.log("Sort: " + sortBy + " Order: " + order);
            });
        });
});

Help-me please.... Thanks

[leodinas-hao]

Hi, @Damien2k9 this query parser only helps parse string to a formatted query object. Then you can use the query object to carry out your query executions. An example like below:

import { MongooseQueryParser } from 'mongoose-query-parser';

const qry = new MongooseQueryParser().parse('sort=name');

// then do you query on your model like following
Product.find(qry.filter || {}).sort(filter.sort);

Or the better way can be add the following extensions to mongoose

function query<T extends Mongoose.Document>(queryOptions: QueryOptions): Promise<T[]> {
  const model = this as Mongoose.Model<T>;

  let chain = model.find(queryOptions.filter || {});
  if (queryOptions.populate) {
    chain = chain.populate(queryOptions.populate);
  }
  if (queryOptions.sort) {
    chain = chain.sort(queryOptions.sort);
  }
  if (queryOptions.limit) {
    chain = chain.limit(queryOptions.limit);
  }
  if (queryOptions.skip) {
    chain = chain.skip(queryOptions.skip);
  }
  if (queryOptions.select) {
    chain = chain.select(queryOptions.select);
  }

  return chain.exec();
}
Mongoose.Model.query = query;

Then you can do query like

router.get('/', (req: Request, res: Response, next: NextFunction) => {
  try {
    const qry = new MongooseQueryParser().parse(req.query);
    YourModel.query(qry).then((orders) => {
      // handle your results
     // ...
    }).catch((err) => {
      next(err);  // failed to query db
    });
  } catch (err) {
    // failed to parse req.query -> invalid user input
    next(new HttpError(422, err));
  }
});