Ytukyg

I need to return the results of a query with mongoose in node.js.

How do you return the value to set the value to a variable?

What I need to do is:

var results = users.findOne({_id : users_list[i]['user_id']},{email : 1, credits : 1},{}, function(err, docs) {

    if( err || !docs) {

        console.log("No user found");

    } else {            

        return docs;

    };

});

In order to have:

results = docs 

Thanks a lot for your reply .

I also have another problem.

How to pass variable in a query operator with find or findOne? Like :

var foo = "Blaa";



users.findOne({_id : users_list[i]['user_id']},{email : 1, credits : 1},{}, function(err, docs) {

    if( err || !docs) {

        console.log("No user found");

    } else {

        // I want to use the foo variable here

        console.log(foo);

    };

});

There are several ways to achieve what you want.

1. Using Mongoose Queries

In this strategy, your function returns a Mongoose query which you can later use to invoke the method exec and use it to get the results.

function getJedisQuery(name){

   var query = Jedi.find({name:name});

   return query;

}

Then you can use it simply doing:

var query =  getJedisQuery('Obi-wan');

query.exec(function(err,jedis){

   if(err)

      return console.log(err);

   jedis.forEach(function(jedi){

      console.log(jedi.name);

   });

});

2. Using Mongoose Promises

Moogose provides support for promises. All you have to do is something somewhat similar to what I did above, but this time, you invoke the exec method without a callback.

function getJedisPromise(name){

   var promise = Jedi.find({name:name}).exec();

   return promise;

}

Then you can use it by simply doing:

var promise = getJedisPromise('Luke');

promise.then(function(jedis){

   jedis.forEach(function(jedi){

      console.log(jedi.name);

   });

}).error(function(error){

   console.log(error);

});

3. Using Mongoose Streams

Finally, Mongoose has also support for streams and streams are event emitters. So, you could get a stream and then subscribe for 'data' and 'error' events. Like this:

function getjedisStream(name){

   var stream = Jedi.find({name:name}).stream();

   return stream;

}

Then you can simply do:

var stream = getJedisStream('Anakin');

stream.on('data', function(jedis){

   jedis.forEach(function(jedi){

      console.log(jedi.name);

   });

});

stream.on('error', function(error){

    console.log(error);

});

Source, for future reference.

it is being executed before the assignment.

async function(req, res) {

  var user;

  await users.findOne({}, function(err,pro){

      user=pro;

    });

  console.log(user); \ it's define



});

You achieve the desired result by the following code. Hope this will helps you a lot..

var async = require('async');



// custom imports

var User = require('../models/user');

var Article = require('../models/article');



var List1Objects = User.find({});

var List2Objects = Article.find({});

var resourcesStack = {

    usersList: List1Objects.exec.bind(List1Objects),

    articlesList: List2Objects.exec.bind(List2Objects),

};



async.parallel(resourcesStack, function (error, resultSet){

    if (error) {

        res.status(500).send(error);

        return;

    }

    res.render('home', resultSet);

});