Spring Boot GraphQL Save, Update and Delete - Database MutationMapping

Learn how to get started with Graphql using spring boot framework. In this session, you will be learning like how to add the schema details and mapping the function and request payload with Graphql @MutationMapping into your controller class. So you can preform like Save, update and delete operation using graphql You need Spring web, JPA, Mysql, Lombok and Spring Graphql dependencies to your pom module.

schema.graphqls (This file should be created inside the resources/graphql folder)

type Query{
    findAll: [User]
    userById(id: ID): User
}

type User{
    id: ID
    name: String
    gender: String
    emailId: String
}

type Mutation{
    addUser(userDetails: UserDetails): User
    updateUser(userDetails: UserDetails): User
    deleteUser(id: ID): String
}

input UserDetails{
    id: ID
    name: String
    gender: String
    emailId: String
}

UserGQLController .java

package com.hakeemit.graphql.controller;

import com.hakeemit.graphql.entity.User;
import com.hakeemit.graphql.entity.UserDetails;
import com.hakeemit.graphql.service.UserServices;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.graphql.data.method.annotation.Argument;
import org.springframework.graphql.data.method.annotation.MutationMapping;
import org.springframework.graphql.data.method.annotation.QueryMapping;
import org.springframework.stereotype.Controller;

import java.util.List;

@Controller
public class UserGQLController {

    @Autowired
    private UserServices userServices;

    @QueryMapping
    public List findAll(){
        return userServices.getAllUser();
    }

    @QueryMapping
    public User userById(@Argument int id){
        return userServices.userById(id);
    }

    @MutationMapping
    public User addUser(@Argument UserDetails userDetails){
        return userServices.add(userDetails);
    }

    @MutationMapping
    public User updateUser(@Argument UserDetails userDetails){
        return userServices.update(userDetails);
    }

    @MutationMapping
    public String deleteUser(@Argument int id){
        return userServices.delete(id);
    }

}

@QueryMapping will be the entry point just like REST API Get Mapping.

UserServices .java

package com.hakeemit.graphql.service;

import com.hakeemit.graphql.entity.User;
import com.hakeemit.graphql.entity.UserDetails;
import com.hakeemit.graphql.repositories.UserRepositories;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;
import java.util.Optional;

@Service
public class UserServices {

    @Autowired
    private UserRepositories userRepositories;

    public User userById(int id){
        Optional user = userRepositories.findById(id);
        return user.get();
    }
    public List getAllUser(){
        return userRepositories.findAll();
    }

    public User add(UserDetails userDetails){
        User user = new User();
        user.setName(userDetails.getName());
        user.setGender(userDetails.getGender());
        user.setEmailId(userDetails.getEmailId());
        return userRepositories.save(user);
    }

    public User update(UserDetails userDetails){
        Optional user = userRepositories.findById(userDetails.getId());
        if(user.isPresent()) {
            user.get().setName(userDetails.getName());
            user.get().setGender(userDetails.getGender());
            user.get().setEmailId(userDetails.getEmailId());
            return userRepositories.save(user.get());
        }
        return null;
    }

    public String delete(int id){
        Optional user = userRepositories.findById(id);
        if(user.isPresent()) {
            userRepositories.delete(user.get());
            return "Deleted";
        }
        return "Failed to delete";
    }
}

pom.xml add the dependencies

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-graphql</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>

<dependency>
    <groupId>com.mysql</groupId>
    <artifactId>mysql-connector-j</artifactId>
    <scope>runtime</scope>
</dependency>

Start running your application 

http://localhost:8080/graphiql?path=/graphql

Video Tutorial Step by Step