在由JoinColumn注释的字段上编写CRUDRepository的findBy()方法

问题描述

我是Spring JPA的新手，所以如果我的问题听起来很简单，我会提前道歉.我有2个实体对象:OrderInfo和PersonInfo.这些类如下:

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;
    }


}

还有Person实体:

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;
    }

}

这两个类是使用JPA的create entityfromtable选项在Eclipse中自动生成的.

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

现在，我正在尝试编写一个CRUDRepository以获取给定orderNumber和personId的OrderInfo.如果我在OrderInfo对象中有一个personId字段，我可能会写类似

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);

}

但是，现在OrderInfo实体没有personId.相反，它具有对Person的引用(同样，我没有编写实体类.它们是由Eclipse自动生成的).我现在应该如何编写findBy()方法?

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?

谢谢.

推荐答案

我找到了另一个解决方案，假设我们有一个User实体和Message实体.

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
}

现在我需要按id_user_sender查找所有消息.

Now i need to find all messages by id_user_sender.

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

外植体:在消息实体中，我有一个名为"userSender"的用户对象. userSender有一个名为"id"的字段.

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

因此'findByUserSenderId'在userSender对象中搜索ID.

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

另一种可能性是将完整的User对象传递到消息存储库，如以下示例所示:(User对象必须仅包含i​​d)

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);
}

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