How to retrieve data using Express GraphQL from mongoDB?

What is GraphQL?

GraphQL is a query language for API’s. It is used to simplify the API specific data processing in which it will fulfill the exact needs and nothing more as like REST API. Data retrieval structure and expectation is decided by client rather than the server. GraphQL isn’t tied to any specific database or storage engine and is instead backed by your existing code and data.

Why GraphQL?

REST API is popular way to consume data in which end point returns all the data which is not fulfilling the data requirement with respect to response data and size in some scenarios. GraphQL will work like query language to fetch the data available in database. Instead of database, GraphQL helps to query the API.

In this post, we are going to see how to retrieve data from mongoDB using express-graphql.

Pre-requisite to install the graphql dependencies;

>npm install express express-graphql graphql mongoose –save

Please refer the previous post to create an express based project in the same blog;

Create a graph.js based on the below code snippet;