Spring Boot とのデータベース統合 : ベスト プラクティスとツール

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

spring:
  datasource:
    url: jdbc:mysql://localhost:3306/mydatabase
    username: root
    password: rootpassword
    driver-class-name: com.mysql.cj.jdbc.Driver
  jpa:
    hibernate:
      ddl-auto: update
    show-sql: true

@Entity
public class User {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    @Column(nullable = false)
    private String name;

    @Column(unique = true, nullable = false)
    private String email;

    // Getters and Setters
}

public interface UserRepository extends JpaRepository<User, Long> {
    Optional<User> findByEmail(String email);
}

@Service
public class UserService {

    @Autowired
    private UserRepository userRepository;

    // Create operation
    public User createUser(User user) {
        // Perform validation or business logic if needed
        return userRepository.save(user);
    }

    // Read operations

    public Optional<User> findUserById(Long id) {
        return userRepository.findById(id);
    }

    public Optional<User> findUserByEmail(String email) {
        return userRepository.findByEmail(email);
    }

    public List<User> getAllUsers() {
        return userRepository.findAll();
    }

    // Update operation
    public User updateUser(Long id, User userDetails) {
        // Ensure the user exists
        User existingUser = userRepository.findById(id)
                .orElseThrow(() -> new ResourceNotFoundException("User not found with id: " + id));

        // Update user details
        existingUser.setName(userDetails.getName());
        existingUser.setEmail(userDetails.getEmail());

        // Save updated user
        return userRepository.save(existingUser);
    }

    // Delete operation
    public void deleteUser(Long id) {
        // Ensure the user exists
        User existingUser = userRepository.findById(id)
                .orElseThrow(() -> new ResourceNotFoundException("User not found with id: " + id));

        // Delete user
        userRepository.delete(existingUser);
    }
}

@ResponseStatus(HttpStatus.NOT_FOUND)
public class ResourceNotFoundException extends RuntimeException {
    public ResourceNotFoundException(String message) {
        super(message);
    }
}

<dependency>
    <groupId>org.flywaydb</groupId>
    <artifactId>flyway-core</artifactId>
</dependency>

spring:
  flyway:
    enabled: true
    locations: classpath:db/migration

-- V1__Initial_Setup.sql
CREATE TABLE user (
    id BIGINT AUTO_INCREMENT PRIMARY KEY,
    name VARCHAR(100) NOT NULL,
    email VARCHAR(100) NOT NULL UNIQUE
);

<dependency>
    <groupId>org.liquibase</groupId>
    <artifactId>liquibase-core</artifactId>
</dependency>

spring:
  liquibase:
    enabled: true
    change-log: classpath:db/changelog/db.changelog-master.yaml

databaseChangeLog:
  - changeSet:
      id: 1
      author: yourname
      changes:
        - createTable:
            tableName: user
            columns:
              - column:
                  name: id
                  type: BIGINT
                  autoIncrement: true
                  constraints:
                    primaryKey: true
              - column:
                  name: name
                  type: VARCHAR(100)
                  constraints:
                    nullable: false
              - column:
                  name: email
                  type: VARCHAR(100)
                  constraints:
                    nullable: false
                    unique: true