In Unit 39 of our e-book course, we will cover a topic that has gained increasing prominence in API development: GraphQL. GraphQL is a query language for APIs and a runtime for running those queries against existing data. It offers a more efficient and powerful alternative to REST and promises greater efficiency for developers.
Before we get into the details of GraphQL, let's understand a little more about its background. GraphQL was developed internally by Facebook in 2012 before being publicly released in 2015. Since then, it has been adopted by many companies and has a rapidly growing developer community.
GraphQL is not a programming language, but a query language for APIs. It allows clients to define the structure of required response data, avoiding data overload and data underutilization. This means that the client has more control over the response data than in REST.
To better understand GraphQL, let's compare it to REST. In REST, to fetch data, you might have to make multiple requests to different endpoints. For example, to get information about a user and their posts, you might have to hit the /user and /user/posts endpoints. However, with GraphQL, you can get all the information you need with a single request to a single endpoint. This makes GraphQL more network efficient than REST.
Also, in REST, the server defines the structure of the response data. This can lead to data glut, where the client is given more data than they really need. However, with GraphQL, the client defines the structure of the response data. This avoids data overload and ensures the customer gets exactly what they need.
Now that we understand what GraphQL is and how it compares to REST, let's dive into how it works. In GraphQL, you define types and fields in your data schemas, as well as functions for each field in your types. These functions are called resolvers and are used to fetch the data for that field.
For example, if you have a User type with id and name fields, you would define resolvers to fetch a user's id and name. When a client makes a query to fetch a user's id and name, GraphQL runs the corresponding resolvers and returns the data.
Additionally, GraphQL supports nested queries, which means you can fetch related data in a single query. For example, you can fetch a user and all of their posts in a single query. This is very powerful and one of the main reasons why GraphQL is so popular.
To implement GraphQL in NodeJS, you can use various libraries such as Apollo Server, Express GraphQL and others. These libraries provide an easy way to create a GraphQL server and define its data schemas and resolvers.
In summary, GraphQL is a powerful and efficient query language for APIs that offers many benefits over REST. It allows customers to define the response data structure, supports nested queries and can be easily implemented in NodeJS with various libraries. In the next unit, we'll delve into how to implement GraphQL in NodeJS and create our first GraphQL API.
We hope you're as excited as we are to get started with GraphQL. Let's continue our learning journey and dive into the wonderful world of GraphQL APIs!
