Writing CRUDRepository's findBy() method on a field annotated by JoinColumn

Question

I'm kind of new to Spring JPA, so I apologize in advance if my question sounds basic. I have 2 entity objects: OrderInfo, and PersonInfo. The classes are as below:

@Entity @Table(name="order_info") @NamedQuery(name="OrderInfo.findAll", query="SELECT o FROM OrderInfo o") public class OrderInfo implements Serializable {      @Column(name="order_number")     private String orderNumber;      //bi-directional many-to-one association to PersonInfo     @ManyToOne     @JoinColumn(name="person_id")     private PersonInfo personInfo;      public String getOrderNumber() {         return this.orderNumber;     }      public void setOrderNumber(String orderNumber) {         this.orderNumber = orderNumber;     }      public PersonInfo getPersonInfo() {         return this.personInfo;     }      public void setPersonInfo(PersonInfo personInfo) {         this.personInfo = personInfo;     }   } 

And the Person entity:

@Entity @Table(name="person_info") @NamedQuery(name="PersonInfo.findAll", query="SELECT p FROM PersonInfo p") public class PersonInfo implements Serializable {      //bi-directional many-to-one association to OrderInfo     @OneToMany(mappedBy="personInfo")     private List<OrderInfo> orderInfos;      public List<OrderInfo> getOrderInfos() {         return this.orderInfos;     }      public void setOrderInfos(List<OrderInfo> orderInfos) {         this.orderInfos = orderInfos;     }      public OrderInfo addOrderInfo(OrderInfo orderInfo) {         getOrderInfos().add(orderInfo);         orderInfo.setPersonInfo(this);          return orderInfo;     }      public OrderInfo removeOrderInfo(OrderInfo orderInfo) {         getOrderInfos().remove(orderInfo);         orderInfo.setPersonInfo(null);          return orderInfo;     }  } 

These two classes were auto-generated in Eclipse using JPA's create entityfromtable option.

Now, I'm trying to write a CRUDRepository to get OrderInfo given an orderNumber, and personId. If I had a personId field in the OrderInfo object, I could have written something like

@Repository public interface OrderRepository extends CrudRepository<OrderInfo, Integer>{     public OrderInfo findByPersonIdAndOrderNumber(@Param("personId") Long personId, @Param("orderNumber") String orderNumber);  } 

However, now the OrderInfo entity does not have a personId. Instead, it has a reference to a Person (Again, I did not write the entity classes. They were auto-generated by Eclipse). How should I write the findBy() method now?

Thanks in advance.

Answer 1

I've found another solution, let's assume we have a User entities and Message entities.

@Entity public class Message {      @Id     @GeneratedValue(strategy = GenerationType.AUTO)     private Long id;      @NotNull     @Type(type="org.jadira.usertype.dateandtime.joda.PersistentDateTime")     private DateTime date;      @ManyToOne     @JoinColumn(name = "id_user_sender")     private User userSender;      @NotNull     private Long idUserReceiver;      @NotNull     @Length(min = 10)     private String message;      @NotNull     private String idConversation;      @NotNull     Boolean userHasRead;      //Getters and Setters  }    @Entity public class User implements Serializable {      @Id     @GeneratedValue(strategy = GenerationType.AUTO)     private Long id;      //Some other properies like email,name etc     //Getters and setters } 

Now i need to find all messages by id_user_sender.

public interface MessageRepository extends JpaRepository<Message,Long>,TransactionRepositoryCustom {     List<Message> findByUserSenderId(Long idUser); } 

Explantion: In the Message entity i have a User Object named 'userSender'. The userSender has a field named 'id'.

So 'findByUserSenderId' search for the id in the userSender Object.

Another possibilty is to pass a full User object to the message repository as in the example below: (The User object must contain only the id)

public interface MessageRepository extends JpaRepository<Message,Long>,TransactionRepositoryCustom {    List<Message> findByUserSender(User user); }