@Entity
@Table(name = "human")
@DynamicInsert(value = true)
@DynamicUpdate(value = true)
public class Human {

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

    @Column(nullable = false, name = "name")
    private String name;

    @ManyToOne(cascade=CascadeType.ALL, fetch=FetchType.LAZY)
    @JoinColumn(name = "parent_id")
    private Human parent;

    @OneToMany(fetch=FetchType.LAZY, mappedBy ="parent")
    private Collection<ProductCategory> subcategories;

    // getters and setters ...
}

@Repository
public interface HumanDao  extends CrudRepository<Human, Long>{
    @Query(value =
            "SELECT * " +
            "FROM humans " +
            "WHERE parent_id = ?1",
            nativeQuery = true)
    public Iterable<Human> getChildren(Long parentId);

}

public class TestClass {

    @Autowired
    private HumanDao dao;

    public void test(Long parentId) {
        Iterable<Human> children = dao.getChildren(parentId);
        System.out.println(children);
    }
}

spring.datasource.url=jdbc:mysql://localhost/db
spring.datasource.username=username
spring.datasource.password=password
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.jpa.properties.max_fetch_depth=1

ID | Name | Parent
1  | Mike | null
2  | John | 1
3  | Bill | 2
4  | Carl | 3