Hello I am trying to filter out for only video_trim in my query but the code still produces empty objects in the place of filtered out content
here is the code
const findTrims = (db, cb) => {
// Get the documents collection
const collection = db.collection(documentName);
// Find some documents
collection.find({}, {projection:{ _id: 0, name: 0, label: 0 }}).toArray((err, docs) => {
// An error occurred we need to return that to the given
// callback function
if (err) {
return cb(err);
}
assert.equal(err, null);
console.log("Found the following records");
console.log(docs)
return cb(null, docs);
});
}
module.exports = {
findTrims: cb => {
MongoClient.connect(url, (err, client) => {
if (err) {
return cb(err)
}
console.log('Connected successfully to server')
const db = client.db(dbName)
findTrims(db, (err, docs) => {
if (err) {
return cb(err)
}
// return your documents back to the given callback
return cb(null, docs)
})
})
}
}
the output of the find is this
[ {}, {}, {}, {}, { Video_trim: ' ' } ]
How do I get rid of the {}?
Pass some conditions to filter. f.e. collection.find({"Video_trim": { $exists: true }}, { _id: 0, name: 0, label: 0 })
Related
I'm trying to set it up so that every time the API query entry in the database it iterates 1 to a value named Popularity, contained inside of that entry.
I have set it up so that it finds the entry then gets ready to edit the Popularity value. Is this the right approach?
router.get("/:ItemID", async (req, res) => {
try {
const updateditem = await Items.findOneAndUpdate(
{ ItemID: req.params.ItemID },
{
$set: {
Popularity: //Previous Value of POPULARITY + 1
}
}
);
res.json(updateditem);
} catch (err) {
console.log(err);
}
});
After Creating your Schema, you just have to update your model in every API hit by using mongoose inc Query
Items.findOneAndUpdate(
{ ItemID: req.params.ItemID },
{ $inc: { Popularity: 1 } },
{ new: true },
function(err, response) {
if (err) {
callback(err);
} else {
callback(response);
}
}
);
or in your code:
router.get("/:ItemID", async (req, res) => {
try {
const updateditem = await Items.findOneAndUpdate(
{ ItemID: req.params.ItemID },
{ $inc: { Popularity: 1 } },
{ new: true },
);
res.json(updateditem);
} catch (err) {
console.log(err);
}
});
I am trying to extend the amount of fields that our API is returning. Right now the API is returning the student info by using find, as well as adding some information of the projects by getting the student info and using findOne to get the info about the project that the student is currently registered to.
I am trying to add some information about the course by using the same logic that I used to get the project information.
So I used the same findOne function that I was using for Projects and my logic is the following.
I created a variable where I can save the courseID and then I will put the contents of that variable in the temp object that sending in a json file.
If I comment out the what I added, the code works perfectly and it returns all the students that I require. However, when I make the additional findOne to get information about the course, it stops returning anything but "{}"
I am going to put a comment on the lines of code that I added, to make it easier to find.
Any sort of help will be highly appreciated!
User.find({
isEnrolled: true,
course: {
$ne: null
}
},
'email pantherID firstName lastName project course',
function(err, users) {
console.log("err, users", err, users);
if (err) {
return res.send(err);
} else if (users) {
var userPromises = [];
users.map(function(user) {
userPromises.push(new Promise(function(resolve, reject) {
///////// Added Code START///////
var courseID;
Course.findOne({
fullName: user.course
}, function(err, course) {
console.log("err, course", err, course);
if (err) {
reject('')
}
courseID = course ? course._id : null
//console.log(tempObj)
resolve(tempObj)
}),
///// ADDED CODE END //////
Project.findOne({
title: user.project
}, function(err, proj) {
console.log("err, proj", err, proj);
if (err) {
reject('')
}
//Course ID, Semester, Semester ID
//map to custom object for MJ
var tempObj = {
email: user.email,
id: user.pantherID,
firstName: user.firstName,
lastName: user.lastName,
middle: null,
valid: true,
projectTitle: user.project,
projectId: proj ? proj._id : null,
course: user.course,
courseId: courseID
}
//console.log(tempObj)
resolve(tempObj)
})
}))
})
//async wait and set
Promise.all(userPromises).then(function(results) {
res.json(results)
}).catch(function(err) {
res.send(err)
})
}
})
using promise could be bit tedious, try using async, this is how i would have done it.
// Make sure User, Course & Project models are required.
const async = require('async');
let getUsers = (cb) => {
Users.find({
isEnrolled: true,
course: {
$ne: null
}
}, 'email pantherID firstName lastName project course', (err, users) => {
if (!err) {
cb(null, users);
} else {
cb(err);
}
});
};
let findCourse = (users, cb) => {
async.each(users, (user, ecb) => {
Project.findOne({title: user.project})
.exec((err, project) => {
if (!err) {
users[users.indexOf(user)].projectId = project._id;
ecb();
} else {
ecb(err);
}
});
}, (err) => {
if (!err) {
cb(null, users);
} else {
cb(err);
}
});
};
let findProject = (users, cb) => {
async.each(users, (user, ecb) => {
Course.findOne({fullName: user.course})
.exec((err, course) => {
if (!err) {
users[users.indexOf(user)].courseId = course._id;
ecb();
} else {
ecb(err);
}
});
}, (err) => {
if (!err) {
cb(null, users);
} else {
cb(err);
}
});
};
// This part of the code belongs at the route scope
async.waterfall([
getUsers,
findCourse,
findProject
], (err, result) => {
if (!err) {
res.send(result);
} else {
return res.send(err);
}
});
Hope this gives better insight on how you could go about with multiple IO transactions on the same request.
req.body.courses has multiples id's of courses that I want to add to a specific categorie, the problem is that when my code runs it save a course more that one time, sometimes four or five times, depending on the number of loops it does.
The function:
router.post('/categories/:cat_id/', function (req, res) {
Categorie.findById(req.params.cat_id, function(err, categorie){
if(err){
console.log(err);
} else {
var courses = req.body.courses;
courses.forEach(function (course){
Course.findOne({ _id: course }, function(err, foundCourse) {
if(err){
console.log(err);
} else {
categorie.courses.push(foundCourse._id);
categorie.save();
}
});
});
}
});
return res.redirect('/dash');
});
The CategorieSchema:
var categorieSchema = mongoose.Schema({
name: String,
courses: [
{
type: mongoose.Schema.Types.ObjectId,
ref: "Course"
}
]
});
Here is an example of trying to add 4 courses to the categorie:
{ "_id" : ObjectId("5a871964a6b4820ecf7abaa7"), "courses" : [ ObjectId("5a870a7374486e0b0d69f710"), ObjectId("5a870a7a74486e0b0d69f711"), ObjectId("5a870a6974486e0b0d69f70f"),
ObjectId("5a870a7374486e0b0d69f710"), ObjectId("5a870a7a74486e0b0d69f711"), ObjectId("5a870a6974486e0b0d69f70f"),
ObjectId("5a870a7374486e0b0d69f710"), ObjectId("5a870a7a74486e0b0d69f711"), ObjectId("5a870a6974486e0b0d69f70f") ], "name" : "test2", "__v" : 3 }
Node.js Is async, It does not wait for the loop to execute completely and each time you are adding _id in existing array because of that adds 2-3 times.
Try this once I have not tested this.
const findOne = (course) => {
return new Promise((resolve, reject) => {
Course.findOne({
_id: course
}, (err, foundCourse) => {
if (err)
return reject(err);
return resolve(foundCourse._id);
});
});
}
router.post('/categories/:cat_id/', function (req, res) {
Categorie.findById(req.params.cat_id, function (err, categorie) {
if (err) {
console.log(err);
res.status(400).json(err);
} else {
var courses = req.body.courses;
Promise.all(courses.map((course) => {
return findOne(course);
})).then((data) => {
// check if course id already there skip
data = data.filter((course) => {
return !categorie.courses.includes(course);
});
categorie.courses = categorie.courses.concat(data);
categorie.save();
return res.redirect('/dash');
}).catch((err) => {
console.log(err);
res.status(400).json(err);
});
}
});
});
An alternative would involve a first query returning the courses using $in operator with Course.find() and then update the courses array in the Categorie model with Categorie.findByIdAndUpdate():
router.post('/categories/:cat_id/', function (req, res) {
Course.find({ '_id': { '$in': req.body.courses }}).exec((err, courses) => {
Categorie.findByIdAndUpdate(
req.params.cat_id,
{ '$addToSet': { 'courses': courses } },
{ 'new': true },
(err, categorie) => {
if (err){
console.log(err);
} else {
return res.redirect('/dash');
}
}
});
});
});
I have a big issue with my function in sails.js (v12). I'm trying to get all userDetail using async (v2.3) for deep populating my user info:
UserController.js:
userDetail: function (req, res) {
var currentUserID = authToken.getUserIDFromToken(req);
async.auto({
//Find the User
user: function (cb) {
User
.findOne({ id: req.params.id })
.populate('userFollowing')
.populate('userFollower')
.populate('trips', { sort: 'createdAt DESC' })
.exec(function (err, foundedUser) {
if (err) {
return res.negotiate(err);
}
if (!foundedUser) {
return res.badRequest();
}
// console.log('foundedUser :', foundedUser);
cb(null, foundedUser);
});
},
//Find me
me: function (cb) {
User
.findOne({ id: currentUserID })
.populate('myLikedTrips')
.populate('userFollowing')
.exec(function (err, user) {
var likedTripIDs = _.pluck(user.myLikedTrips, 'id');
var followingUserIDs = _.pluck(user.userFollowing, 'id');
cb(null, { likedTripIDs, followingUserIDs });
});
},
populatedTrip: ['user', function (results, cb) {
Trip.find({ id: _.pluck(results.user.trips, 'id') })
.populate('comments')
.populate('likes')
.exec(function (err, tripsResults) {
if (err) {
return res.negotiate(err);
}
if (!tripsResults) {
return res.badRequest();
}
cb(null, _.indexBy(tripsResults, 'id'));
});
}],
isLiked: ['populatedTrip', 'me', 'user', function (results, cb) {
var me = results.me;
async.map(results.user.trips, function (trip, callback) {
trip = results.populatedTrip[trip.id];
if (_.contains(me.likedTripIDs, trip.id)) {
trip.hasLiked = true;
} else {
trip.hasLiked = false;
}
callback(null, trip);
}, function (err, isLikedTrip) {
if (err) {
return res.negotiate(err);
}
cb(null, isLikedTrip);
});
}]
},
function finish(err, data) {
if (err) {
console.log('err = ', err);
return res.serverError(err);
}
var userFinal = data.user;
//userFinal.trips = data.isLiked;
userFinal.trips = "test";
return res.json(userFinal);
}
);
},
I tried almost everthing to get this fix but nothing is working...
I am able to get my array of trips(data.isLiked) but I couldn't get my userFInal trips.
I try to set string value on the userFinal.trips:
JSON response
{
"trips": [], // <-- my pb is here !!
"userFollower": [
{
"user": "5777fce1eeef472a1d69bafb",
"follower": "57e44a8997974abc646b29ca",
"id": "57efa5cf605b94666aca0f11"
}
],
"userFollowing": [
{
"user": "57e44a8997974abc646b29ca",
"follower": "5777fce1eeef472a1d69bafb",
"id": "5882099b9c0c9543706d74f6"
}
],
"email": "test2#test.com",
"userName": "dany",
"isPrivate": false,
"bio": "Hello",
"id": "5777fce1eeef472a1d69bafb"
}
Question
How should I do to get my array of trips (isLiked) paste to my user trips array?
Why my results is not what I'm expecting to have?
Thank you for your answers.
Use .toJSON() before overwriting any association in model.
Otherwise default toJSON implementation overrides any changes made to model associated data.
var userFinal = data.user.toJSON(); // Use of toJSON
userFinal.trips = data.isLiked;
return res.json(userFinal);
On another note, use JS .map or _.map in place of async.map as there is not asynchronous operation in inside function. Otherwise you may face RangeError: Maximum call stack size exceeded issue.
Also, it might be better to return any response from final callback only. (Remove res.negotiate, res.badRequest from async.auto's first argument). It allows to make response method terminal
I'm trying to do a push or pull based on a condition, along with an upsert
myCollection.update(
{'id': location},
{
$set: { count },
$setOnInsert: {
id: location,
users: []
},
},
{
$cond: {
if: (increment==1),
then: {$push: { users: userToken }},
else: {$pull: { users: userToken }}
}
},
{'upsert':true},
(err, data) => {
...
I'm trying to DRY this up (which works):
mongo.connect(dbUrl, (err, db) => {
if (err) throw err
let myCollection = db.collection('myCollection')
if(increment==1){
myCollection.update(
{'id': location},
{
$set: { count },
$push: { users: userToken },
$setOnInsert: {
id: location
}
},
{'upsert':true},
(err, data) => {
if (err) throw err
console.log(data);
callback()
db.close()
}
)
}
else{
myCollection.update(
...
$pull: { users: userToken },
...
)
}
})
It's not adding anything to the DB when I have $cond. Where should the $cond be?
$cond is not applicable here but in the aggregation framework. What you need is a pure old native JS conditional statement where you create the update document prior to using it in the update operation, and this of course should be set in a condition block. Consider the following example:
let queryObj = { 'id': location },
usersObj = { 'users': userToken },
updateObj = {
'$set': { count },
'$setOnInsert': queryObj
},
options = { 'upsert': true },
updateOperator = '$pull';
if (increment == 1) updateOperator = '$push';
updateObj[updateOperator] = usersObj;
myCollection.update(queryObj, updateObj, options,
(err, data) => {
if (err) throw err
console.log(data);
callback();
db.close();
}
)