1. Add spring-boot-starter-data-jpa dependency to pom.xml. You may skip version tag, if you are using spring-boot-starter-parent as the parent of your pom.xml. The dependency below brings Hibernate and everything related to JPA to your project (reference).

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

2. Add database driver to pom.xml. This one below is for H2 database (reference).

   <dependency>
       <groupId>com.h2database</groupId>
       <artifactId>h2</artifactId>
   </dependency>
   

3. Enable debug logging for Hibernate in application.properties

   logging.level.org.hibernate.SQL = debug

or in application.yml

logging:
  level:
    org.hibernate.SQL: debug

4. Add entity class to desired package under ${project.home}/src/main/java/, for example under com.example.myproject.domain (reference):

   package com.example.myproject.domain;
   
   import javax.persistence.Column;
   import javax.persistence.Entity;
   import javax.persistence.GeneratedValue;
   import javax.persistence.Id;
   import java.io.Serializable;
   
   @Entity
   public class City implements Serializable {
   
       @Id
       @GeneratedValue
       public Long id;
   
       @Column(nullable = false)
       public String name;
   }
   

5. Add import.sql to ${project.home}/src/main/resources/. Put INSERT statements into the file. This file will be used for database schema population on each start of the app (reference):

   insert into city(name) values ('Brisbane');
   
   insert into city(name) values ('Melbourne');
   

6. Add Repository class to desired package under ${project.home}/src/main/java/, for example under com.example.myproject.service (reference):

   package com.example.myproject.service;
   
   import javax.persistence.Column;
   import javax.persistence.Entity;
   import javax.persistence.GeneratedValue;
   import javax.persistence.Id;
   import java.io.Serializable;
   
   import com.example.myproject.domain.City;
   import org.springframework.data.domain.Page;
   import org.springframework.data.domain.Pageable;
   import org.springframework.data.repository.Repository;
   
   interface CityRepository extends Repository<City, Long> {
   
       Page<City> findAll(Pageable pageable);
   
       Page<City> findByName(String name);
   }
   

Basically that's it! At this point you already can access the database using the methods of com.example.myproject.service.CityRepository.

1. Add spring-boot-starter-web dependency to pom.xml. You may skip version tag, if you are using spring-boot-starter-parent as the parent of your pom.xml (reference).

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

2. Add REST controller to desired package, for example to com.example.myproject.web.rest (reference):

   package com.example.myproject.web.rest;
   
   import java.util.Map;
   import java.util.HashMap;
   import org.springframework.beans.factory.annotation.Autowired;
   import org.springframework.http.ResponseEntity;
   import org.springframework.web.bind.annotation.RequestMapping;
   import org.springframework.web.bind.annotation.RestController;
   
   import javax.servlet.http.HttpServletRequest;
   
   @RestController
   public class VersionController {
       @RequestMapping("/api/version")
       public ResponseEntity get() {
           final Map<String, String> responseParams = new HashMap();
           responseParams.put("requestStatus", "OK");
           responseParams.put("version", "0.1-SNAPSHOT");
   
           return ResponseEntity.ok().body(responseParams.build());
       }
   }    
   

3. Start Spring Boot application (reference).

4. Your controller is accessible at the address http://localhost:8080/api/version.