Let's say I have a database with two collections, kids and classes. Each kid belongs to one class.
Each class has a previously created integer id.
I want to replace the kid.class_id with the (ObjectID) _id of the class, not the (integer) id of the class.
However, when I run the script below, it doesn't reset the class_id with the class._id -- it remains the old integer id.
mongoose.connect(someMongodbUri, { useMongoClient: true }, (err, db) => {
let kidsCount = 0;
db.collection('kids').find({}).each((err, kid) => {
kidsCount++;
db.collection('classes')
.findOne({ id: kid.class_id })
.then((class, err) => {
let newClassId = class._id;
db.collection('kids').updateOne(
{ _id: kid._id },
{ $set: { class_id: newClassId } }
).then(() => {
console.info('Updated', kid.class_id);
kidsCount--;
if (kidsCount === 0) { db.close(); }
});
});
});
});
Am I missing something? Thanks for any help you can offer!
We can convert integerId to Object id.
var ObjectId = require('mongodb').ObjectID;
let newClassId = ObjectId(class._id);
There may be better or elegent ways that i don't know, but this works for me.
Related
Basically what I want to do is that I have an ObjectId of a qr. I want to use that ObjectId to find out which qrBlock does it belong. Im leaving my dbmodel here
so you can track easily.
qrRoute.post("/scanQr", (req, res) => {
let { data } = req.body;
var id = mongoose.Types.ObjectId(data);
Qr.findById(id)
.exec()
.then((qrr) => {
QrBlock.find({ qr: { "qr.$": id } }, (qrblck) => {
console.log(qrblck);
});
});
});
I tried this code above it didn't work.
did you try this way
qrRoute.post("/scanQr", (req, res) => {
let { data } = req.body;
var id = mongoose.Types.ObjectId(data);
Qr.findById(id)
.exec()
.then((qrr) => {
QrBlock.find({ qr: id }, (qrblck) => {
console.log(qrblck);
});
});
});
QrBlock.findOne({ qr: { $all: [qrr._id] } })
this worked for me
I have defined a PostSchema as follows. A post is written by an author, and can be read by many people: lastOpens is an array of { time: ... , userId: ... }.
var PostSchema = new mongoose.Schema({
title: { type: String }
author: { type: mongoose.Schema.Types.ObjectId, ref: 'user' },
lastOpens: { type: Array, default: [] }
})
Now, I want to write a static method that returns all the posts read by one user:
PostSchema.statics.postsOpenedByUser = function (userId, cb) {
// need to go through all the posts, and check their `lastOpens`.
// If `userId` is in `userId` of a `lastOpen`, then count the post in
}
What I know is the methods like find({ ... }) of MongoDB. But I don't know how to specify a more complicated search like mine.
Could anyone help?
Edit 1: I tried to use $where operator as follows, it did not work:
PostSchema.statics.postsOpenedByUser = function (userId, cb) {
return this.find({ $where: function () {
var index = -1;
for (var i = 0; i < this.lastOpens.length; i++)
if (this.lastOpens[i].userId === userId) { index = i; break }
return !(index === -1)
}}, cb)
Is there anything we could not do inside $where?
You can use Mongo's query an array of embedded documents.
In your case it will look something like :
PostSchema.statics.postsOpenedByUser = function (userId, cb) {
return this.find( { "lastOpens.userId" : userId }, cb );
}
This will return all posts that have userId in the lastOpens
Ok so here is what I am trying to do, I have a Item collection that holds a users items along with price quantity and description. I have also created a collection called soldItems that will store information about a sold item once the user inputs the required data and submits the form. I am not sure if I am doing this correctly to begin with and I have been trying to research this but I don't exactly know what I am looking for.
Here is the code I have so far
router.post("/item/:id", middleware.isLoggedIn, (req, res) => {
Item.findById(req.params.id, (err, item) => {
if(err) {
console.log(err);
}
var soldItem = {
id: req.params.id,
item: req.item.name,
askPrice: req.item.price
};
var soldPrice = req.body.soldPrice;
var soldQuantity = req.body.soldQuantity;
var itemSold = {
soldItem: soldItem,
soldPrice: soldPrice,
soldQuantity: soldQuantity
};
SoldItem.create(itemSold, (err, newlyCreated) => {
if (err) {
console.log(err);
} else {
item.soldItems.push(newlyCreated);
item.save();
req.flash("success", "Item Sold");
res.redirect("back");
}
});
});
});
So... Item.findById(req.params.id) works because I am pulling the ObjectId from the url. However, how would I be able to use req.item._id. Because the issue I am having is when I am trying to get req.item.name and req.item.price I am being told that it cannot read property 'name' or 'price' of undefined. How can I get that information?
I am trying to use the Waterline .native() method to query an item by id in the database. This is what my code looks like:
// Consutruct the query based on type
var query = {};
if (req.param('type') === 'id') {
query = { _id: req.param('number') };
} else {
query = { 'data.confirmationNumber': req.param('number') };
}
Confirmations.native(function(error, collection) {
if (error) {
ResponseService.send(res, 'error', 500, 'Database error.');
} else {
collection.find(query).toArray(function(queryError, queryRecord) {
if (queryError) {
ResponseService.send(res, 'error', 500, 'Database error.');
} else {
if (queryRecord.length > 0) {
ResponseService.send(res, 'success', 200, queryRecord[0]);
} else {
ResponseService.send(res, 'error', 404, 'Your confirmation details could not be found.');
}
}
});
}
});
When the query is 'data.confirmationNumber' it works but if it is '_id' it dows not work. How do I fix this?
if your Id is a ObjectId see this
var ObjectId = require('mongodb').ObjectID;
{_id: new ObjectId(req.param('number') )}
Iniside Model and in attribute define the id field like this
id : {type : 'objectid',primaryKey:true}
When you are querying the code
Here my model name is - QuizModel and the id is coming in the params quizId so here quizId is equal to the _id in the mongodb database
QuizModel.find({_id: QuizModel.mongo.objectId(quizId)})
.then(function(response){
})
.catch(function(error){
});
I would like to increment the views count by 1 each time my document is accessed. So far, my code is:
Document
.find({})
.sort('date', -1)
.limit(limit)
.exec();
Where does $inc fit in here?
Never used mongoose but quickly looking over the docs here it seems like this will work for you:
# create query conditions and update variables
var conditions = { },
update = { $inc: { views: 1 }};
# update documents matching condition
Model.update(conditions, update).limit(limit).sort('date', -1).exec();
Cheers and good luck!
I ran into another problem, which is kind of related to $inc.. So I'll post it here as it might help somebody else. I have the following code:
var Schema = require('models/schema.js');
var exports = module.exports = {};
exports.increase = function(id, key, amount, callback){
Schema.findByIdAndUpdate(id, { $inc: { key: amount }}, function(err, data){
//error handling
}
}
from a different module I would call something like
var saver = require('./saver.js');
saver.increase('555f49f1f9e81ecaf14f4748', 'counter', 1, function(err,data){
//error handling
}
However, this would not increase the desired counter. Apparently it is not allowed to directly pass the key into the update object. This has something to do with the syntax for string literals in object field names. The solution was to define the update object like this:
exports.increase = function(id, key, amount, callback){
var update = {};
update['$inc'] = {};
update['$inc'][key] = amount;
Schema.findByIdAndUpdate(id, update, function(err, data){
//error handling
}
}
Works for me (mongoose 5.7)
blogRouter.put("/:id", async (request, response) => {
try {
const updatedBlog = await Blog.findByIdAndUpdate(
request.params.id,
{
$inc: { likes: 1 }
},
{ new: true } //to return the new document
);
response.json(updatedBlog);
} catch (error) {
response.status(400).end();
}
});