@Entity
@Table(name = "users")
public class User {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

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

    @Column(nullable = false)
    private String firstName;

    @Column(nullable = false)
    private String lastName;

    @CreationTimestamp
    private LocalDateTime createdAt;

    @UpdateTimestamp
    private LocalDateTime updatedAt;

    // Constructors, getters, and setters
    public User() {}

    public User(String email, String firstName, String lastName) {
        this.email = email;
        this.firstName = firstName;
        this.lastName = lastName;
    }

    // Getters and setters omitted for brevity
}

@Repository
public interface UserRepository extends JpaRepository<User, Long> {

    // Query methods derived from method names
    List<User> findByFirstNameContainingIgnoreCase(String firstName);

    Optional<User> findByEmail(String email);

    List<User> findByCreatedAtBetween(LocalDateTime start, LocalDateTime end);

    // Custom JPQL queries
    @Query("SELECT u FROM User u WHERE u.firstName = :firstName AND u.lastName = :lastName")
    List<User> findByFullName(@Param("firstName") String firstName, @Param("lastName") String lastName);

    // Native SQL queries
    @Query(value = "SELECT * FROM users WHERE created_at > DATE_SUB(NOW(), INTERVAL 30 DAY)", nativeQuery = true)
    List<User> findRecentUsers();

    // Modifying queries
    @Modifying
    @Query("UPDATE User u SET u.firstName = :firstName WHERE u.id = :id")
    int updateFirstName(@Param("id") Long id, @Param("firstName") String firstName);
}

spring:
  datasource:
    url: jdbc:postgresql://localhost:5432/myapp
    username: ${DB_USERNAME:admin}
    password: ${DB_PASSWORD:password}
    driver-class-name: org.postgresql.Driver

  jpa:
    hibernate:
      ddl-auto: validate
    show-sql: false
    properties:
      hibernate:
        dialect: org.hibernate.dialect.PostgreSQLDialect
        format_sql: true
    database-platform: org.hibernate.dialect.PostgreSQLDialect