GraphQL is a query language for APIs that allows clients to request specific data fields from resources in a single request. It provides database independence, acts as an API middleware, and allows APIs to evolve without versioning by defining types and fields. This document demonstrates how to build a basic GraphQL API using Node.js, Express, and GraphQL tools like GraphiQL by defining a schema, root query, and relationships between types.

1. Hands On - Building your first GraphQL API

2. “GraphQL is a query language for your API, and a
server-side runtime for executing queries by using a
type system you define for your data.”

3. SQL
GraphQL Language
Express, Spring Boot or any REST framework
GraphQL Runtime

4. ● Open-source project maintained by Facebook
● An REST alternative
● You ask for what you need, get exactly that
● Get many resources in a single request
● Describe what’s possible with a type system
● Used by GitHub, Coursera, Twitter, Shopify...
What is that?

5. Why we need this?
● Database independence
● API translate/middleware
● Easily plug into your existing code
● You define your types and fields
● Evolve your API without versions
● Self-documented

6. Show me the code!

7. package.json

9. json-server

12. server.js

14. schema.js

16. Customer Type

18. Root Query Object
your “/” endpoint

20. GraphiQL IDE

24. Relationships and Mutations

25. Ecosystem Support
github.com/graphql/graphql-js
github.com/graphql-java/graphql-java
...

26. More Examples
funfun function
/watch?v=lAJWHHUz8_8
/watch?v=RMtq0RCLuzs

27. github.com/brenohq/graphql-server

28. The End