Updating an array of numbers in Mongoose: A guide

Question

Updating an array of numbers in Mongoose: A guide

I am having trouble updating an array within a MongoDB document using Mongoose. Below is my stock model definition:

const ticker = new mongoose.Schema({
   ticker: String,
   Price: Number,
   Amount: Number,
   PastPrices: [Number]
});
export const stock = mongoose.model("Stocks", ticker);

Here is an example document in MongoDB:

{
  "_id": {
    "$oid": "61e5d0e1dfda4d7c85dc8fe2"
  },
  "PastPrices": [
    2
  ],
  "ticker": "TSLA",
  "Price": 2,
  "Amount": 0,
  "__v": 0
}

Despite running the update operation with Mongoose, the PastPrices array is not being updated as expected. My goal is to continuously add values to this array every few seconds and eventually display them on a chart.

 stock.updateOne({ticker: "TSLA"},
        { $push: { PastPrices:1}}
    );

No error messages are being displayed, but the array is simply not updating as intended.

javascript typescript mongodb mongoose mongodb-query

Answer 1

Answer №1

updateOne function doesn't immediately execute the update operation, instead it returns a Query object. The Mongoose Queries guide explains this concept:

You can execute a mongoose query in two ways. Firstly, by passing a callback function to Mongoose, the query will be executed asynchronously and the results will be passed to the callback function.

Additionally, a query has a .then() function and can be treated as a Promise.

This means that you can pass a callback function as shown in the query execution documentation:

const Person = mongoose.model('Person', yourSchema);
// Find a person with last name 'Ghost' and retrieve `name` and `occupation`
Person.findOne({ 'name.last': 'Ghost' }, 'name occupation', function (err, person) {
 if (err) return handleError(err);
 // Output: "Space Ghost is a talk show host"
  console.log('%s %s is a %s.', person.name.first, person.name.last,
    person.occupation);
});

You also have the option to use then() or exec() for handling Promises. As mentioned in the Mongoose promise documentation:

const query = Band.findOne({name: "Guns N' Roses"});
assert.ok(!(query instanceof Promise));

 // A query is not a fully-fledged promise, but it does have a `.then()`.
query.then(function(doc) {
 // do something with doc
});

// Using `.exec()` provides a complete promise
const promise = Band.findOne({name: "Guns N' Roses"}).exec();
assert.ok(promise instanceof Promise);

promise.then(function (doc) {
  // handle doc
});

If you are in an async context, you can utilize await on the query:

await stock.updateOne({ticker: "TSLA"},
        { $push: { PastPrices:1}}
    );

Answer 2

updateOne function doesn't immediately execute the update operation, instead it returns a Query object. The Mongoose Queries guide explains this concept:

You can execute a mongoose query in two ways. Firstly, by passing a callback function to Mongoose, the query will be executed asynchronously and the results will be passed to the callback function.

Additionally, a query has a .then() function and can be treated as a Promise.

This means that you can pass a callback function as shown in the query execution documentation:

const Person = mongoose.model('Person', yourSchema);
// Find a person with last name 'Ghost' and retrieve `name` and `occupation`
Person.findOne({ 'name.last': 'Ghost' }, 'name occupation', function (err, person) {
 if (err) return handleError(err);
 // Output: "Space Ghost is a talk show host"
  console.log('%s %s is a %s.', person.name.first, person.name.last,
    person.occupation);
});

You also have the option to use then() or exec() for handling Promises. As mentioned in the Mongoose promise documentation:

const query = Band.findOne({name: "Guns N' Roses"});
assert.ok(!(query instanceof Promise));

 // A query is not a fully-fledged promise, but it does have a `.then()`.
query.then(function(doc) {
 // do something with doc
});

// Using `.exec()` provides a complete promise
const promise = Band.findOne({name: "Guns N' Roses"}).exec();
assert.ok(promise instanceof Promise);

promise.then(function (doc) {
  // handle doc
});

If you are in an async context, you can utilize await on the query:

await stock.updateOne({ticker: "TSLA"},
        { $push: { PastPrices:1}}
    );

Answer 3

Answer №2

Your inquiry is accurate, however, to ensure that the query fetches updated data, you must include an additional configuration { new: true }. Omitting this may result in the query updating the data but returning outdated information.

stock.updateOne(
  { ticker: "TSLA" },
  { $push: { PastPrices:1 } },
  { new: true }
);

Answer 4

Your inquiry is accurate, however, to ensure that the query fetches updated data, you must include an additional configuration { new: true }. Omitting this may result in the query updating the data but returning outdated information.

stock.updateOne(
  { ticker: "TSLA" },
  { $push: { PastPrices:1 } },
  { new: true }
);

Updating an array of numbers in Mongoose: A guide

Answer №1

Answer №2

Similar questions

Is it possible for me to add a string to a URL as long as the string is not null?

What is the process for reporting a security vulnerability in an npm package if you are the maintainer and publisher?

Having images that are too large in size and using a high percentage can

Difficulty in aligning the text of the ListItem

Having difficulty applying capitalization to the initial word in an input using JavaScript/jQuery

Converting a Symfony2 DateTime object from MongoDB: a step-by-step guide

Changing the style of characters within a contenteditable element

How do I retrieve unique values for a field while applying other conditions in pymongo queries?

V-Calendar is not displaying the accurate dates

Selecting keys of an object in Angular 2

Tips for documenting curried functions using Js docs

Decimal tally in React using JavaScript

Persisting a modal in NextJS on page refresh - navigating with elegance

Encountered MissingSchemaError when implementing the mongoose-observer tool

Unable to update React state on a component that is unmounted while utilizing Redux

What is the best way to utilize a random user agent in Scrapy while integrating with Py

What are the steps for integrating Angularfire2 into an Angular application?

CORS blocked in the live environment

Chapter 5 of Eloquent JavaScript's 3rd Edition presents Exercise 3

Unique mongoose schema with 2 different fields