README.md

Demo Application - GraphQL with Spring Boot

Reference Documentation

For further reference, please consider the following sections:

• Official Apache Maven documentation
• Spring Boot Maven Plugin Reference Guide
• Create an OCI image
• Spring Web
• Spring Data JPA

Guides

The following guides illustrate how to use some features concretely:

• Building a RESTful Web Service
• Serving Web Content with Spring MVC
• Building REST services with Spring
• Accessing Data with JPA
• GraphQL - Getting started with Spring Boot

My personal notes

Demo application with H2 database to test some GraphQL features.

Notes

• GraphQL Query - GET data
• GraphQL Mutation - Create, Update, Delete data
• GraphQL Schema - Define which attributes are there in your class data type.
• GraphQL Vs REST API:
  • REST is having fixed response while GraphQL provides flexibility;
  • REST has different http methods and separate endpoints to each API, while in GraphQL whe have Query and Mutation and there is only one endpoint;
  • GraphQL needs Schema file while REST does not need that.
• Node and Edge in GraphQL:
  • Node(Table - PK) ---->(Edge) Node(Table - PK; FK)

Examples

• Plugin for Google Chrome to run querys: Altair GraphQL Client

• Query's:

  query {
        fullName(sampleRequest: {
            firstName: "Tiago",
            lastName: "Jesus"
        })
  }
  

  Get Student By Id (dynamic fields, can add or remove fields):

  query {
      student(id: 1){
          id
          firstName
          lastName
          email
          street
          city
      }
  }
  

  Query with list:

    query{
          student(id: 2){
              id
              firstName
              lastName
              learningSubjects {
                  subjectName
                  marksObtained
              }
          }
    }
  

      query{
          student(id: 2){
              id
              firstName
              lastName
              learningSubjects {
                  subjectName
                  marksObtained
              }
              fullName
          }
      }
  

  Query with filtered data:

  • subjectNameFilter (Enum): All, Java, MySQL, MongoDB

    query{
        student(id: 2){
            id
            firstName
            lastName
            learningSubjects(subjectNameFilter: Java) {
                subjectName
                marksObtained
            }
          fullName
        }
    }
  

  Query to create (Mutation - POST):

        mutation{
          createStudent(createStudentDTO:{
                firstName: "TM"
                lastName: "91"
                email: "tm91@test.com"
                street: "test"
                city: "test"
                subjectsLearning: [
                  { subjectName: "Java" marksObtained: 100.00 }
                  { subjectName: "Ruby" marksObtained: 60.00 }
                ]
              }) {
                id
                firstName
                lastName
                email
                street
                city
                learningSubjects(subjectNameFilter: All) {
                  id
                  subjectName
                  marksObtained
                }
                fullName
              }
          }
        }