What is GraphQL: Definition & Uses

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What is GraphQL?

Harold Bell

Key Takeaway

GraphQL is a query language and runtime for APIs (Application Programming Interfaces) that was developed by Facebook. It provides a more efficient and flexible way to request and manipulate data from servers compared to traditional RESTful APIs. With GraphQL, clients can specify the exact data they need, avoiding over-fetching or under-fetching of information.

GraphQL is a query language for APIs. It was created by Facebook engineers in 2015 and has since become popular among developers working on large-scale web applications. Positioned as a more robust alternative to traditional RESTful APIs, GraphQL is built on the principles of Graph Theory, which are a set of mathematical concepts that describe how networks of objects (nodes) interact with each other.

GraphQL makes it easy to query APIs by allowing you to express your requests in a precise and concise manner. Similar to how you would communicate with a friend about where to go for dinner or what to do over the weekend, you can describe to the API what you are looking for using variables and filters, and get exactly what you want back. Some popular implementations of GraphQL include Facebook’s GraphQL, GitHub’s GraphQL API and Salesforce’s App Cloud Connect service.

Why use GraphQL?

There are several reasons why you might want to use GraphQL instead of traditional RESTful APIs. First, GraphQL is more powerful. It allows you to specify exactly what data you want, rather than allowing the API provider to decide which resources to return for you. Second, GraphQL makes it easier to write your queries by using a simple and intuitive syntax. Rather than building a complex URL with many parameters, you can express your request in a single line or a few lines. Finally, because GraphQL has been designed to work across multiple clients including web browsers and mobile devices, it can support many different use cases and applications.

How is GraphQL used?

GraphQL is typically used with a client application, such as a web browser or a mobile application. The client application requests data from the API using GraphQL and parses the response into a readable format. For example, you might use GraphQL to get information about a user account from an API provider such as Facebook. This response would be processed on the client by converting the JSON result to HTML, then sent to the user’s web browser. Alternatively, you could use GraphQL to request a list of products from an API provider such as Amazon. The response would be parsed by the JavaScript in the client application which would generate an HTML page for the user to view the list of products. In both these examples, the client application would be able to process the result because it speaks GraphQL.

GraphQL vs REST

GraphQL is a query language and API platform that builds on the strengths of REST. It is also completely compatible with RESTful APIs. Many developers who are familiar with REST APIs find that GraphQL makes working with APIs much easier and quicker. However, there are some stark differences between the two. The main difference between a traditional REST API and a GraphQL API is that with the former, you have to define how you’re going to make requests to each individual endpoint. With a GraphQL API, you define your queries in one place and the server takes care of making the requests for you.

Other notable differences between GraphQL and REST include:

Query language – With REST you have a list of resources and verbs (methods) available to select from in order to retrieve or manipulate data from the server, and all transactions include all fields. With GraphQL you have a query language that allows you to specify precisely what data fields you want to interact with.
Resource structure – With REST, the server returns a list of resources; with GraphQL, the server can return a single object or collection of objects.
Queries vs requests – In REST you make a request with a method/verb request and you retrieve one or more resources as a result; with GraphQL you make a query that returns data. Requests are more complex because they require JSON to be parsed and processed on the server before the results can be returned; queries are simpler because they are written in the native language of the client, which eliminates much of the overhead associated with handling requests and parsing JSON.

Here’s a simple example of a query using a traditional REST API and a GraphQL API: If you request data from the traditional REST API using GET or POST, the response you get back might look something like this: { ‘data’: [ { ‘name’: ‘John Smith’, ‘age’: 50 }, { ‘name’: ‘Jane Doe’, ‘age’: 20 } ] } If you want more details of a specific user from the data above, you have to re-query the API with another endpoint specifying the user’s name, like this: … GET /users/:name . You can see that using a GraphQL API would be much simpler. You could simply say: Give me the profile of John Smith, and the server would return data about John Smith as a response.

There are pros and cons to both approaches, but in the end it comes down to what works best for your specific application. If you’re not sure which approach to take, it’s always a good idea to start by consulting with your team’s developers or architects who can help you choose the best solution for your needs.

Disadvantages of GraphQL

One of the biggest drawbacks to using GraphQL is that there currently isn’t an official standard when it comes to implementing GraphQL APIs, so developers will have to rely on the open source community to come up with tools and libraries that make working with GraphQL easier.

Also, though it would seem that GraphQL is a clear winner over REST APIs, there are some things to consider. GraphQL has fewer endpoints available than REST does because it is designed to return smaller pieces of data as results. This means you often have to do more work to get all of the data that you might need from an API using GraphQL. You can mitigate this by using code-generation tools that automatically generate entire codebases for you from your GraphQL schema, but it takes more work upfront to set it up than it might to set up a REST API. There are also more developer tools available to help debug a REST API than there are for debugging a GraphQL API.

Securing your GraphQL API

GraphQL APIs are rich targets for hackers and should be secured as best as possible. One of the best ways to protect your GraphQL APIs is to make sure that you use a secured authentication system that requires an API key be sent with each query and restricts access based on roles that your users are granted. You should also use HTTPS to encrypt your queries and prevent eavesdropping by third-party users.

For maximum protection, you should use tools that detect misconfigurations and provide runtime protection that monitor data access in real time and alert you to unexpected or unauthorized activity on your API. With the right API security tools in place, you can quickly respond to any security threats and protect your data from being stolen.