Merchant.js
module.exports = {
attributes: {
name:{
type:'string',
required:true
},
drinks:{
collection:'Drinks',
via:'merchant'
}
}
};
Drinks.js
module.exports = {
attributes: {
name:{
type:'string',
required:true
},
category:{
model:'Category'
},
merchant:{
model:'Merchant'
}
}
};
Category.js
module.exports = {
attributes: {
name:{
type:'string',
required:true,
unique: true
}
}
};
I want to retrieve the merchant with the drinks associated with the given input category.
Can someone help me in the find query.
Thanks
var selectedCategory;//given input category.
async.waterfall([
function(callback) {
Drinks
.find({
category: selectedCategory
})
.exec(function(err, drinks) {
if (err) return callback(err);
callback(null, drinks);
});
},
function(drinks, callback) {
Merchant.find({
drinks: drinks //In Pairs
})
.populate('drinks')
.exec(function(err, merchants) {
if (err) return callback(err);
callback(null, merchants);
});
}
],
function(err, results) {
if (err) return res.badRequest(err);
res.ok(results);
});
$in also didn't meet my requirement. I didn't find any sails support.
So I changed my logic as in the following :
var selectedCategory = req.param("value");
async.waterfall([
function(callback) {
Category
.findOne({
name: selectedCategory
})
.exec(function(err, cat) {
if (err) return callback(err);
callback(null, cat);
});
},
function(cat,callback) {
Drinks
.find({
category: cat.id
}).populateAll()
.exec(function(err, drinks) {
if (err) return callback(err);
callback(null, drinks);
});
},
function(drinks, callback) {
var merchantIds = [];// to store unique merchant ids
drinks.forEach(function (drink) {
if (merchantIds.indexOf(drink.merchant.id) < 0) {
merchantIds.push(drink.merchant.id);
}
})
callback(null, drinks,merchantIds);
},
function(drinks,merchantIds, callback) {
Merchant
.find({ where: {'id': {"$in": merchantIds}},skip:page*perPage,limit:perPage}).populateAll()
.exec(function (err, merchantList) {
if (err) return callback(err);
callback(null, drinks,merchantList);
});
},
function(drinks,merchantList, callback) {
var merchantsList = [];
merchantList.forEach(function (merchant) {
var merchants={};//to store merchant details in JSON format
merchants['id'] = merchant.id;
merchants['name'] = merchant.name;
merchants['drinks']=[]
drinks.forEach(function (drink) {
if (merchant.id===drink.merchant.id) {
merchants['drinks'].push(drink);
}
})
merchantsList.push(merchants)
})
callback(null, merchantsList);
}
],
function(err, results) {
if (err) return res.badRequest(err);
res.json(results);
});
Related
I am a noobie in coding and I am having an issue with how to use properly MongoDB. I have a parent object classroom containing an array of objects - comments. I am trying to update the content of 1 selected comment.
originally I updated the state of the whole "classroom" in the react and passed all the data and $set {req.body} in findByIdAndUpdate.
I want to achieve the same result if I only pass to my axios request classId, commentId and comment data and not whole classroom / all comments
I tried to filter selected comment out of the array of comments and concat updated comment, but that did not work. Clearly, I have any idea what is going on and docs don't make it any easier for me to understand.
my classroom schema:
var ClassroomSchema = new Schema({
title: String,
teacher: String,
info: String,
image_url: String,
comments: [Comment.schema]
});
comment schema:
var CommentSchema = new Schema()
CommentSchema.add({
content: String,
comments: [CommentSchema],
created_at: {
type: Date,
default: Date.now
}
});
original solution:
function update(req, res){
Comment.findById(req.params.comment_id, function(err, comment) {
if(err) res.send(err)
comment.content = req.body.content;
comment.save();
console.log(req.body.comments)
Classroom.findByIdAndUpdate(req.params.classroom_id,
{$set: req.body}, function(err, classroom){
if (err) {
console.log(err);
res.send(err);
} else {
commentToUpdate = req.body.commentData;
res.json(classroom);
}
});
});
}
my current failing atempt:
function update(req, res){
console.log('update => req.body: ', req.body);
console.log('req.params', req.params)
Comment.findById(req.params.comment_id, function(err, comment) {
if(err) res.send(err)
comment.content = req.body.content;
comment.save();
console.log('comment: ', comment);
Classroom.findById(req.params.classroom_id, function(err, classroom) {
console.log('CLASSROOM findByIdAndUpdate classroom: ', classroom)
// console.log('reg.body: ', req.body)
if (err) {
console.warn('Error updating comment', err);
res.send(err);
} else {
// commentToUpdate = req.body.commentData;
old_comments = classroom.comments;
console.log('comments: ', old_comments);
Classroom.findByIdAndUpdate(req.params.classroom_id,
{$set:
{ comments: old_comments.filter(comt._id !== comment._id).concat(comment)}
}, function(err, updatedClassroom) {
if (err) {
console.warn(err);
} else {
res.json(updatedClassroom);
}
});
}
});
});
}
haven't tested, but try this.
function update(req, res) {
Classroom.update(
{ _id: req.params.classroom_id, "comments._id": req.params.comment_id },
{ $set: { "comments.$.content": req.body.content } },
function(err) {
..
}
);
}
I want to increment id's automatically in the mongoDB while posting the data. I am able to attach date for the req.body. How to attach ids with auto incrementation?
This is my post call:
router.post('/addVisualization', function (req, res, next) {
MongoClient.connect(url, function (err, db) {
if (err) throw err;
var dbo = db.db(dbName);
req.body.dateOfEntry = new Date();
function getNextSequence(id) {
var ret = db.counters.findAndModify(
{
query: { _id: id },
update: { $inc: { seq: 1 } },
new: true
}
);
return ret.seq;
}
dbo.collection("visualization").insertOne(req.body, function (err, resDB) {
if (err) {
throw err;
res.status(401);
res.send({
"status": 401,
"message": "Some error happened"
});
}
else {
console.log("1 document inserted");
res.status(201)
res.send({
"body": req.body,
"status": 201,
"message": "visualization has been added"
});
}
});
db.close();
});
});
Try out the below code to auto increment id's in mongoDB.
router.post('/addVisualization', function (req, res, next) {
MongoClient.connect(url, {
useNewUrlParser: true
}, function (err, db) {
if (err) throw err;
var dbo = db.db(dbName);
req.body.dateOfEntry = new Date();
req.body.isDeleted = "false";
var countRow;
var sequenceDocument = dbo.collection("counterVisualization").findOneAndUpdate({
_id: "tid"
}, {
$inc: {
sequence_value: 1
}
}, {
new: true
});
dbo.collection("counterVisualization").find({
_id: "tid"
}).toArray(function (err, result1) {
if (err) {
throw err;
} else {
countRow = result1[0].sequence_value;
req.body["_id"] = countRow;
dbo.collection("visualization").insertOne(req.body, function (err, resDB) {
if (err) {
throw err;
res.status(401);
res.send({
"status": 401,
"message": "Some error happened"
});
} else {
console.log("1 document inserted");
res.status(201)
res.send({
"body": req.body,
"status": 201,
"message": "visualization has been added"
});
}
});
}
});
});
});
In mongo db you don't have a auto increment ids as mysql or oracle, Please take a look at this tutorial for how to do it out of the box.
Use a separate counters collection to track the last id of the sequence.
db.counters.insert(
{
_id: "userid",
seq: 0
}
)
db.counters.insert(
{
_id: "productid",
seq: 0
}
)
Create a getNextSequence function that accepts a name of the sequence.
function getNextSequence(name) {
var ret = db.counters.findAndModify(
{
query: { _id: name },
update: { $inc: { seq: 1 } },
new: true,
upsert : true // Creates a new document if no documents match the query
}
);
return ret.seq;
}
Use this getNextSequence() function during insert.
db.users.insert(
{
_id: getNextSequence("userid"),
name: "Mr. X",
// ... more fields
}
)
db.products.insert(
{
_id: getNextSequence("productid"),
name: "Mr. Y",
// ... more fields
}
)
Been banging my head in the wall on this, so any help would be greatly appreciated. With MongooseJS, I'm doing a Model.find and then looping through those results and doing a findAndUpdate.
(basically, get list of URLS from MongooseJS, "ping" each URL to get a status, then update the DB with the status).
Schema
var serverSchema = new Schema({
github_id: { type: String, required: true },
url: { type: String, required: true },
check_interval: Number,
last_check: {
response_code: Number,
message: String,
time: Date
},
created_at: Date,
updated_at: Date
})
Here's a code snippet:
// Doesn't work
Server.find(function (err, items) {
if (err) return console.log(err)
items.forEach(function (item) {
var query = {url: item.url}
Server.findOneAndUpdate(query, {updated_at: Date.now()}, function (err, doc) {
if (err) return console.log(err)
console.log(doc)
})
})
})
// Works!
var query = {url: 'https://google.com'}
Server.findOneAndUpdate(query, {updated_at: Date.now()}, function (err, doc) {
if (err) return console.log(err)
console.log(doc)
})
With debugging on, I can see that the .find() is getting the data I want. However, it seems that he findOneAndUpdate within the .find() never runs (item.url is set correctly) and I don't get any errors, it just doesn't run.
Any help would be GREATLY appreciated.
You can achieve that without find and then update you can do this in only one update operation
Server.update({}, { $set: { updated_at: Date.now() } }, function(err, doc) {
if (err) return console.log(err) {
console.log(doc)
}
})
In case you need to loop on items for specific reason to handle urls then try the code below
var Server = require('../models/server');
Server.find(function(err, items) {
if (err) {
return console.log(err)
} else {
items.forEach(function(item) {
var query = { url: item.url }
Server.update(query, { $set: { updated_at: Date.now() } }, function(err, doc) {
if (err) return console.log(err)
console.log(doc)
})
})
}
})
Mongodb Connection:
var secrets = require('./secrets');
var mongoose = require('mongoose');
module.exports = function() {
var connect = function() {
var mongoLink = "";
if (process.env.NODE_ENV === 'production') {
mongoLink = secrets.db.prod;
} else {
mongoLink = secrets.db.dev;
}
mongoose.connect(mongoLink, function(err, res) {
if (err) {
console.log('Error connecting to: ' + mongoLink + '. ' + err);
} else {
console.log('Connected to: ' + mongoLink);
}
});
};
connect();
mongoose.connection.on('error', console.log);
mongoose.connection.on('disconnected', connect);
}
This is my MongoDB schema:
var partnerSchema = new mongoose.Schema({
name: String,
products: [
{
type: mongoose.Schema.Types.ObjectId,
ref: 'Product'
}]
});
var productSchema = new mongoose.Schema({
name: String,
campaign: [
{
type: mongoose.Schema.Types.ObjectId,
ref: 'Campaign'
}
]
});
var campaignSchema = new mongoose.Schema({
name: String,
});
module.exports = {
Partner: mongoose.model('Partner', partnerSchema),
Product: mongoose.model('Product', productSchema),
Campaign: mongoose.model('Campaign', campaignSchema)
}
And I wondering how can I remove object from any document taking into account references (maybe should I use somehow populate from mongoose)? For example if I will remove Product then I assume that I will remove also ref ID in Partner and all Campaigns which belong to this Product.
At the moment I removing in this way:
var campSchema = require('../model/camp-schema');
router.post('/removeProduct', function (req, res) {
campSchema.Product.findOneAndRemove({ _id: req.body.productId }, function (err, response) {
if (err) throw err;
res.json(response);
});
});
However in mongo still left references.
You would have to nest your calls to remove the product id from the other model. For instance, in your call to remove the product from the Product
collection, you could also make another call to remove the ref from the Partner model within the results callback. Removing the product by default will remove its refs to the Campaign Model.
The following code shows the intuition above:
var campSchema = require('../model/camp-schema');
router.post('/removeProduct', function (req, res) {
campSchema.Product.findOneAndRemove({ _id: req.body.productId }, function (err, response) {
if (err) throw err;
campSchema.Partner.update(
{ "products": req.body.productId },
{ "$pull": { "products": req.body.productId } },
function (err, res){
if (err) throw err;
res.json(res);
}
);
});
});
To remove the associated campaigns then you may need an extra remove operation that takes in the associated campaign id fro a given product id. Consider the following dirty hack which may potentially award you a one-way ticket to callback hell if not careful with the callback nesting:
router.post('/removeProduct', function (req, res) {
campSchema.Product.findOneAndRemove(
{ _id: req.body.productId },
{ new: true },
function (err, product) {
if (err) throw err;
campSchema.Partner.update(
{ "products": req.body.productId },
{ "$pull": { "products": req.body.productId } },
function (err, res){
if (err) throw err;
var campaignList = product.campaign
campSchema.Campaign.remove({ "_id": { "$in": campaignList } })
.exec(function (err, res){
if (err) throw err;
res.json(product);
})
}
);
}
);
});
Although it works, the above potential pitfall can be avoided by using async/await or the async library. But firstly, to give you a better understanding of the using multiple callbacks with the async module, let's illustrate this with an example from Seven Things You Should Stop Doing with Node.js of multiple operations with callbacks to find a parent entity, then find child entities that belong to the parent:
methodA(function(a){
methodB(function(b){
methodC(function(c){
methodD(function(d){
// Final callback code
})
})
})
})
With async/await, your calls will be restructured structured as
router.post('/removeProduct', async (req, res) => {
try {
const product = await campSchema.Product.findOneAndRemove(
{ _id: req.body.productId },
{ new: true }
)
await campSchema.Partner.update(
{ "products": req.body.productId },
{ "$pull": { "products": req.body.productId } }
)
await campSchema.Campaign.remove({ "_id": { "$in": product.campaign } })
res.json(product)
} catch(err) {
throw err
}
})
With the async module, you can either use the series method to address the use of callbacks for nesting code of multiple methods which may result in Callback Hell:
Series:
async.series([
function(callback){
// code a
callback(null, 'a')
},
function(callback){
// code b
callback(null, 'b')
},
function(callback){
// code c
callback(null, 'c')
},
function(callback){
// code d
callback(null, 'd')
}],
// optional callback
function(err, results){
// results is ['a', 'b', 'c', 'd']
// final callback code
}
)
Or the waterfall:
async.waterfall([
function(callback){
// code a
callback(null, 'a', 'b')
},
function(arg1, arg2, callback){
// arg1 is equals 'a' and arg2 is 'b'
// Code c
callback(null, 'c')
},
function(arg1, callback){
// arg1 is 'c'
// code d
callback(null, 'd');
}], function (err, result) {
// result is 'd'
}
)
Now going back to your code, using the async waterfall method you could then restructure your code to
router.post('/removeProduct', function (req, res) {
async.waterfall([
function (callback) {
// code a: Remove Product
campSchema.Product.findOneAndRemove(
{ _id: req.body.productId },
function (err, product) {
if (err) callback(err);
callback(null, product);
}
);
},
function (doc, callback) {
// code b: Remove associated campaigns
var campaignList = doc.campaign;
campSchema.Campaign
.remove({ "_id": { "$in": campaignList } })
.exec(function (err, res) {
if (err) callback(err);
callback(null, doc);
}
);
},
function (doc, callback) {
// code c: Remove related partner
campSchema.Partner.update(
{ "products": doc._id },
{ "$pull": { "products": doc._id } },
function (err, res) {
if (err) callback(err);
callback(null, doc);
}
);
}
], function (err, result) {
if (err) throw err;
res.json(result); // OUTPUT OK
});
});
I'm new using sails JS.
I have methods like this
beforeDestroy: function(borrow, next){
return Book.find({id:borrow.product})
.then(function(){
Book.update(borrow.product, {'isBorrowed' : false})
})
.then(function(){
next();
})
.catch(function(error){
next(error);
});
}
When I tried to destroy data book 'IsBorrowed' still true, how to fix this when tried t delete data, firstly find id and secondly, change data book IsBorrowed to be false? Thank Advance
Here is a solution (to your original question - just switch the isBorrowed logic around as you now need it):
book.js
module.exports = {
schema: true,
attributes: {
name: {type: 'string', required: true},
desc: {type: 'text'},
isBorrowed: {type: 'boolean', defaultsTo: false}
}
};
bookBorrowed.js
module.exports = {
schema: true,
attributes: {
book: {model: 'Book'}
},
beforeDestroy: function (criteria, next) {
var bookId = criteria.where.id;
console.log(bookId);
Book.update({id: bookId}, {isBorrowed: true})
.exec(function (err, updatedBook) {
if (err) {
next('no book..');
}
console.log('updated book', updatedBook);
next();
});
}
};
Your problem was that you should consider the relationship with id, not object.
Also, the criteria parameter passed into beforeDestroy has a where object, it isn't the model. Also, the update() function takes an object criteria, see above.
If you wish to test, replace your bootstrap.js with the following snippet:
module.exports.bootstrap = function (cb) {
var bk = {name: 'name', desc: 'desc', isBorrowed: false};
Book.create(bk).exec(function (err, book) {
if (err) {
cb(err);
}
console.log('book: ', book);
var bb = {book: book.id};
BookBorrowed.create(bb).exec(function (err, bkBorrowed) {
if (err) {
cb(err);
}
console.log('bkBorrowed: ', bkBorrowed);
BookBorrowed.destroy({id: bkBorrowed.id}).exec(function (err, bkBorrowed) {
if (err) {
cb(err);
}
cb();
});
})
});
};