使用spring数据连接三个实体

Question

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

@ManyToOne
@JoinColumn( name = "owner" )
private ffperson;
private String constructor;
//getters and setters

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

@Column( name = "name" )
private String Name;
//getters and setters

@Column( name = "lastname", unique = true )
private String lastName;

@Column( name = "firstname", unique = true )
private String firstName;

@Column( name = "birth_date", unique = true )
private Date   dateOfBirth;

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

@ManyToOne
@JoinColumn( name = "dog_id" )
private ffdog;

@ManyToOne
@JoinColumn( name = "person_id" )
private ffperson;

我想用spring数据写一个查询，可以找到所有有自己的狗和车的人…可以有任何身体帮助吗

Answer 1

更新您的实体，如下所示：

人

@Entity
@Table(name = "person")
public class Person {

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

    @OneToMany(mappedBy = "person", cascade = CascadeType.ALL)
    Set<Dog> dogs = new HashSet<>();

    @OneToMany(mappedBy = "person", cascade = CascadeType.ALL)
    Set<Car> cars = new HashSet<>();

    ...

}

狗狗

@Entity
@Table(name="dog")
public class Dog {

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

    @Column( name = "name" )
    private String Name;

    @ManyToOne
    private Person person;

    ...

}

汽车

@Entity
@Table(name = "car")
public class Car {

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

    @ManyToOne
    private Person person;

    ...

}

public interface PersonRepository extends CrudRepository<Person, Long> {

    @Query("select p from Person p join fetch p.dogs join fetch p.cars")
    List<Person> findAll();

}