Question

我试图在Spring MVC应用程序中连接到我的数据库。有两张桌子。用户和订单，用户有一个主键列：“userID”，订单具有来自列的复合键：“userID”和“orderID”，其中userID是引用Users表中“userID”列的外键。

以下是我的课程：

订单：

@Entity
@Table(name = "Orders")
@IdClass(OrderPK.class)
public class Order implements Serializable{

    private static final Long serialVersionUID = 1L;

    @EmbeddedId
    private OrderPK orderPK;

    //other properties

    //no args and full args constructor

    //getters and setters

    //toString

}

OrderPK：

@Embeddable
public class OrderPK implements Serializable {
    @Column(name = "orderID")
    private Long orderID;

    @ManyToOne
    @JoinColumn(name = "userID")
    private User user;

    public OrderPK() {
    }

    public OrderPK(Long orderID, User user) {
        this.orderID = orderID;
        this.user = user;
    }

    public Long getOrderID() {
        return orderID;
    }

    public void setOrderID(Long orderID) {
        this.orderID = orderID;
    }

    public User getUser() {
        return user;
    }

    public void setUser(User user) {
        this.user = user;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (!(o instanceof OrderPK)) return false;
        OrderPK that = (OrderPK) o;
        return Objects.equals(getOrderID(), that.getOrderID()) &&
            Objects.equals(getUser(), that.getUser());
    }

    @Override
    public int hashCode() {
        return Objects.hash(getOrderID(), getUser());
    }
}

用户：

@Entity
@Table(name = "USERS")
public class User implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @SequenceGenerator(name="USER_SEQUENCE", sequenceName="USER_SEQUENCE")
    @GeneratedValue(strategy=GenerationType.SEQUENCE, 
    generator="USER_SEQUENCE")
    @Column(name = "userid")
    private Long userId;

    //other properties

    //no args and full args constructor

    //getters and setters

    //toString
}

当我尝试连接到数据库时，我得到以下异常：

org.springframework.beans.factory.BeanCreationException：在类路径资源中定义名称为'entityManagerFactory'的bean时出错[org / springframework / boot / autoconfigure / orm / jpa / HibernateJpaAutoConfiguration.class]：init方法的调用失败;嵌套异常是org.hibernate.AnnotationException：无法在使用@IdClass注释的实体中查找属性（orderID，user）：com.ex.evemarketback.domain.Order

...

引起：org.hibernate.AnnotationException：无法在使用@IdClass注释的实体中找到属性（orderID，user）：com.ex.evemarketback.domain.Order

有什么建议吗？

Answer 1

当您使用@EmbeddedId时，您不需要@IdClass注释：

@Entity
@Table(name = "Orders")
public class Order implements Serializable{

或者如果你想保留@IdClass：

// @Embeddable - no need for that
public class OrderPK implements Serializable {
    private Long orderID;
    private Long userId;

    ...
}

实体：

@Entity
@Table(name = "Orders")
@IdClass(OrderPK.class)
public class Order implements Serializable{

    @Id
    @Column(name = "orderID")
    private Long orderID;

    @Id
    @Column(name = "userId", insertable=false, updatable=false)
    private Long userId;

    @ManyToOne
    @JoinColumn(name = "userID")
    private User user;

Spring-data-JPA，其中外键引用Composite Key中的“UserID”，试图映射到列“user”而不是UserID

1 个答案: