Once the server process the client request, the result needs to be sent back to the client. Express provides various methods to send the result like res.send(), res.json(), res.redirect(). In today’s post, we are going to see res.json(). res.json() is a utility wrapper around res.send() that also adds the Content-Type: application/json header to the response. This header […]
REST APIs support multiple parameter types like: Header, Query String, Path & Request body. Routing refers to how an application’s endpoints (URIs) respond to client requests. Here, we will cover how can your server access path or route parameters. These parameters are a part of the url itself eg. GET /client/93 Express Router params Express Router parameters are specific attributes […]
An array is a single variable in JavaScript which holds multiple elements inside it. Each element inside the array has a unique index assigned to it. You can access the element inside the array using that index. Array can be changed or mutated with many built in methods. Let’s cover some methods to add new […]
There are various HTTP methods available to access data or send data to the server. HTTP provides get, post, put, patch, delete methods. In today’s post we are going to use Post method with the help of AJAX. AJAX stands for Asynchronous JavaScript And XML, which allows the webpage to be updated in the backgroud […]
In this article, you will learn about the mongoose populate. From version 3.2 or above, MongoDB has the join, like $lookup aggregation operator. But in mongoose, you will get a more powerful alternative which name is populate(). It will let you reference documents in other collections. In mongoose, Populate is the way of replacing a […]
In this article, you are going to know about eslintignore.ESLint is a tool that inspects your ECMAScript/JavaScript code and points out issues based on some pre-defined rules. It focused on make the code more consistent and avoid unwanted bugs. Sometimes you need to ignore a file. If you want a particular file not to be […]
In this article, you will learn about how to use Mongoose findOneAndUpdate In Mongoose there are many effective methods for updating data. Each method is designed for a single purpose but they work differently. One of these methods is findOneAndUpdate(). Mongoose’s findOneAndUpdate() function finds the first document that matches a given filter, then applies an […]
In this article, you will learn about how to use the Chai assertion library.Assertion libraries are tools to verify that things are correct. Basically, It helps you to test your code and reduce your time by preventing writing thousands of if statements. Chai is an assertion library. More specifically, Chai is a BDD / TDD […]
In this article, You will learn how to use Mongoose timestamps. Mongoose schemas have a timestamps option that informs Mongoose to automatically manage createdAt and updatedAt properties on your documents. Everything in Mongoose starts with a Schema. MongoDB collection maps each schema and within that collection, it defines the shape of the documents. Let’s assume […]
In this article, you are going to learn about Mongoose aggregation. In MongoDB, the aggregation pipeline consists of stages and each stage transforms the document. It is extremely powerful and very handy to use. Mongoose comes with aggregate() function by which you can use MongoDB’s aggregation framework with Mongoose. Basically, it is a thin wrapper […]
Mongoose provides various methods to update the document like .save(), findOneAndUpdate(), updateOne(). In today’s post we are going to use findOneAndUpdate(). findOneAndUpdate(): There are multiple documents saved inside mongoDB which match the criteria of update condition. findOneAndUpdate method matches the first document that satisfies the condition & updates it. By default, findOneAndUpdate() returns the original […]
The then() method returns a Promise. It takes up to two arguments: callback functions for the success and failure cases of the Promise. Promises can be chained one after the other using the .then() chain. The subsequent promises in .then chain are only executed once the current promise resolves successfully. If the current promise rejects […]
In JavaScript, Promises are used to denote an ongoing task which has not completed yet. It may Resolve with a result or Reject with an error. It can take an infinite amount of time to complete something internally. A promise may have more promises within it. Promises can be chained one after the another to […]
Each document inside MongoDB has a unique id associated with it, which helps to identify the document independently. It is similar to primary key defined in MySQL. findById: This method takes Id as input parameter & returns the single matching document. FindById is shortcut of findOne({ _id: id }) example: Once a user hits this […]
In this article, You will learn how to get all documents in Mongoose. Let assume, you have a mongoose model User that has all your app’s users information. Now, to get all users list from the mongoose collection you have to call User.find() with an empty object as the first parameter. It will search for […]
