Mongoose - MongoDB | "Query was already executed" error on query in loop - mongodb

I'm trying to collection queries in the while loop. But I'm getting a "Query was already executed" error. How can I do that? I have a custom field and I need to make sure it is unique. I also need to use this function elsewhere.
async function createRandomID() {
let id = Math.random().toString(36).slice(2, 6).toUpperCase();
let unique = false;
while (!unique) {
await Deed.findOne({ deedId: id }, async (err, doc) => {
if (!doc) {
unique = true;
}
else {
id = Math.random().toString(36).slice(2, 6).toUpperCase();
}
})
}
return id;
}
const addNewDeed = asyncErrorWrapper(async (req, res, next) => {
let information = req.body;
const deedId = await createRandomID();
/*Other Operations...*/
});

Related

Order of save() and find() in NodeJS with MongoDB

I'm trying to create a new record in my MongoDB ("thisPlayer") and save it to my database, then find all records in my database (including the new one) and render them.
I am having trouble understanding why my save() function actually occurs after my find() function. When this code executes, the find() function does not include my new thisPlayer record. However, after the find() runs, the save occurs -- the record is saved to the database AFTER the find() ran.
Thanks in advance!
const playerNumber = async function countPlayers() {
return new Promise((resolve, reject) => {
Player.count(function(err, numOfDocs) {
err ? reject(err) : resolve(numOfDocs);
console.log('I have '+numOfDocs+' documents in my collection');
});
});
}
async function playerProfile() {
var count = await playerNumber();
console.log("count already in db: "+ count);
if (count===0) {
teamCaptain=1;
} else {teamCaptain=0};
count++;
const thisPlayer = new Player({
playerNum: count,
playerName: Name,
});
thisPlayer.save();
Player.find({}, function(err, playaz){
var playerOne;
if (playaz.length > 0) {
playerOne = playaz[0].playerName;
} else {
playerOne = "";
}
res.renderPjax("leavetakings",
{player1: "1: " + playerOne}
);
});
}
playerProfile();
You need to use await
for example.
await Player.find({})

How to check if value already exists in the data received from api before inserting it into db

I am having hard times trying to write data received from a api to db.
I successfully got data and then have to write it to db. The point is to check whether the quote is already exists in my collection.
The problem I am dealing with is that every value gets inserted in my collection, not regarding if it exists or not.
const { MongoClient } = require('mongodb')
const mongoUrl = 'mongodb://localhost/kanye_quotes'
async function connectToDb() {
const client = new MongoClient(mongoUrl, { useNewUrlParser: true })
await client.connect()
db = client.db()
}
async function addQuote(data) {
await connectToDb()
try {
const collection = db.collection('quotes')
let quotes = [];
quotes = await collection.find({}).toArray()
if (quotes = []) { // I added this piece of code because if not check for [], no values will be inserted
collection.insertOne(data, (err, result) => {
if (err) {
return
}
console.log(result.insertedId);
return
})
}
quotes.forEach(quote => {
if (quote.quote !== data.quote) { // I compare received data with data in collection, it actually works fine(the comparison works as it supposed to)
collection.insertOne(data, (err, result) => {
if (err) {
return
}
console.log(result.insertedId);
})
} else console.log('repeated value found'); // repeated value gets inserted. Why?
})
}
catch (err) {
console.log(err)
}
}
Hi it's probably better to set unique: true indexing on your schema. That way you won't have duplicated values.

How to retrieve currentUser data with Vue.js, AWS Amplify, and MongoDB

I am attempting to build a Vue.js App that synthesizes properties of AWS, MongoDB, and Express. I built an authentication page for the app using aws-amplify and aws-amplify-vue. After logging into the app, metadata containing the username for the logged in AWS user is passed into data object property this.name like so:
async beforeCreate() {
let name = await Auth.currentAuthenticatedUser()
this.name = name.username
}
this.name is then added to MongoDB via Axios:
async addName() {
let uri = 'http://localhost:4000/messages/add';
await this.axios.post(uri, {
name: this.name,
})
this.getMessage()
}
I also have a getName() method that I am using to retrieve that data from MongoDB:
async getData () {
let uri = 'http://localhost:4000/messages';
this.axios.get(uri).then(response => {
this.userData = response.data;
});
},
This method, however, returns data for ALL users. I want to reconfigure this method to ONLY return data for .currentAuthenticatedUser(). In my previous experience with Firebase, I would set up my .getData() method with something like:
let ref = db.collection('users')
let snapshot = await ref.where('user_id', '==', firebase.auth().currentUser.uid).get()
...in order to return currentUser information on the condition that 'user_id' in the collection matches the currently logged-in Firebase user.
To achieve this with MongoDB, I attempted to configure the above method like so:
async getData () {
let uri = 'http://localhost:4000/messages';
let snapshot = await uri.where('name', '==', this.name);
this.axios.get(snapshot).then(response => {
this.userData = response.data;
});
},
My thought here was to try and return current user data by comparing 'name' in the MongoDB collection with the logged-in user stored in this.name...but I understand that this might not work because the .where() method is probably unique to Firebase. Any recommendations on how to configure this .getData() to return ONLY data associated with the currentAuthenticatedUser? Thanks!
EXPRESS ROUTES:
const express = require('express');
const postRoutes = express.Router();
// Require Post model in our routes module
let Post = require('./post.model');
// Defined store route
postRoutes.route('/add').post(function (req, res) {
let post = new Post(req.body);
post.save()
.then(() => {
res.status(200).json({'business': 'business in added successfully'});
})
.catch(() => {
res.status(400).send("unable to save to database");
});
});
// Defined get data(index or listing) route
postRoutes.route('/').get(function (req, res) {
Post.find(function(err, posts){
if(err){
res.json(err);
}
else {
res.json(posts);
}
});
});
module.exports = postRoutes;
It is not possible to apply a where clause to a uri AFAIK. What you should do is adding a where clause to the actual query you are making in your backend and, to do that, send the username you want to filter the query with through a query parameter like this: /messages?name=JohnDoe.
So basically if you are using a Node/Express backend, as you suggested, and using Mongoose as the ODM for MongoDB your request would probably be looking something like this:
const Users = require('../models/users.model');
Users.find({}, function (e, users) {
if (e) {
return res.status(500).json({
'error': e
})
}
res.status(200).json({
'data': users
});
})
What you should do is getting the username query parameter through req.query and add it to the options in the first parameter of the find function.
const Users = require('../models/users.model');
let params = {},
name = req.query.name;
if (name) {
params.name = name
}
Users.find(params, function (e, users) {
if (e) {
return res.status(500).json({
'error': e
})
}
res.status(200).json({
'data': users.slice
});
})
That way if you point to /messages?name=John you will get the users with "John" as their name.
Edit:
If your backend is configured in the following way
postRoutes.route('/').get(function (req, res) {
Post.find(function(err, posts){
if(err){
res.json(err);
}
else {
res.json(posts);
}
});
});
what you should do is get the query parameters from inside the get method
postRoutes.route('/').get(function (req, res) {
let params = {},
name = req.query.name
if (name) {
params.name = name
}
Post.find(params, function(err, posts){
if(err){
res.json(err);
}
else {
res.json(posts);
}
});
});

Migrating callbacks to Async

I'm struggling with migrating a HAPI function that verifies a JWT token and then makes a database call using the decoded credentials.
The problem is that jwt.verify uses a callback, but Hapi and Hapi.MySQL2 have both been updated to use async functions
The main function is as follows
exports.LoadAuth = (req, h) => {
let token = req.headers.authorization.split(' ')[1]
VerifyToken(token, async function (err, decoded) {
if (!err) {
let sql = '#SELECT STATEMENT USING decoded.id'
const [data] = await mfjobs.query(sql, decoded.id)
let auids = []
data.forEach(function (ag) {
auids.push(ag.Name)
})
auids = base64(auids.toString())
return auids
} else {
return {message: 'Not Authorised'}
}
})
}
The VerifyToken function is as follows:
VerifyToken = (tok, done) => {
jwt.verify(tok, Buffer.from(secret, 'base64'), function (err, decTok) {
if (err) {
done(err)
} else {
done(null, decTok)
}
})
}
Debugging everything above works up to the point that the data should be returned to the front end. At which point I get an ERROR 500
I know that the issue is with the VerifyToken function as if I omit this and hard code the decoded.id into the query the correct data reaches the front end.
Any pointers?
You can convert your VerifyToken function to Promises.
let VerifyToken = (tok) => {
return new Promise((resolve, reject) => {
jwt.verify(tok, Buffer.from(secret, 'base64'), function (err, decTok) {
if (err) {
reject(err)
} else {
resolve(decTok)
}
})
});
}
Now you have a function that you can use with async await notation and internally checks jwt validation via callbacks.
Then we can slightly modify your controller as follows.
exports.LoadAuth = async (req, h) => {
let token = req.headers.authorization.split(' ')[1];
try {
let decoded = await VerifyToken(token);
let sql = '#SELECT STATEMENT USING decoded.id';
const [data] = await mfjobs.query(sql, decoded.id);
let auids = [];
data.forEach(function (ag) {
auids.push(ag.Name)
});
auids = base64(auids.toString());
return auids
} catch (e) {
return {message: 'Not Authorised'}
}
}
We just converted your handler function to async function, and we already have a VerifyToken function that returns a promise so, we can call it with the await operator.

Waiting for meteor cursor in method

I have a large aggrogate query that required me to pass "allowDiskUse: true" as an option. This would not work with the aggegate as described here:
https://github.com/meteorhacks/meteor-aggregate/issues/11
My meteor method is defined here. When I call the method I need to wait for ondata to complete before anything is returned to the client, but nothing I try allows me to get that data in a safe way up to the front end.
Meteor.methods({
'getSummary': function (dept,startDate,endDate,filterType) {
f = myQuery(startdate,enddate,dayFinalGroup);
f.on("data", Meteor.bindEnvironment(function(row) {
//load an array or something here to return
}));
f.once("end", Meteor.bindEnvironment(function() {
// tidy up, in my case end the stream
}));
//here I'd return the array loaded
},
});
This is my front end.
Meteor.call(
'getSummary',0,Session.get('start_date'),Session.get('end_date'),1,
function(error, result){
if(error){
console.log(error);
} else {
Session.set('sumTotals',result);
}
}
);
Finally Got it. I utilized wrapSync
'getSummary': function (dept,startDate,endDate,filterType) {
console.log(dept);
console.log(startDate);
console.log(endDate);
console.log(filterType);
var startdate = new Date(startDate);
var enddate = new Date(endDate);
var arr = [];
f = myQuery(startdate,enddate,dayFinalGroup);
var fetchCursor = Meteor.wrapAsync(function fetchCursor (cursor, cb) {
cursor.each(function (err, doc) {
if (err) return cb(err);
if (!doc) return cb(null, { done: true }); // no more documents
arr.push(doc);
});
});
var myData = fetchCursor(f);
return arr;