GraphQL is a query language created by Facebook that provides a common interface for clients to efficiently fetch data from multiple backend services and APIs. It addresses issues with traditional REST APIs like overfetching data and needing multiple requests to fetch related resources. To use GraphQL, you first define a schema, implement it, add permissions, then clients can execute queries against the schema to retrieve precisely the data they need in one request.

1. GraphQL
query language and runtime

2. Restful API and microservice
Application
Application
Application
API
API
API
API
API

3. Multi Request
Too many REST API calls on a
page?

4. API Versioning

5. Others
1. Requirement change
2. Overfetching of data
3. API based on data not product

6. What’s GraphQL
GraphQL is a query language created by Facebook which provides a common
interface between the client and the server for data fetching and manipulations

7. Who are using GraphQL

8. How SQL works with database

9. What GraphQL need
1. Define schema
2. Implement the schema
3. Add custom permissions
4. Write some GraphQL queries
5. Client execute queries

10. Schema

11. graphql-java

12. GraphQL queries

13. Demo

14. Way to use it

15. Way to use it

16. Thanks