我有订单,它可以有很多状态。尝试保存新状态似乎不适用于单向关系。这是正确的,我不能保存从订单到状态的单向关系的状态,如我的代码所示?有什么可能的方法来保存它?
表:订单(PK_ORDER_ID,ORDER_NO)
表:ORDER_STATUS(PK_ORDER_STATUS_ID,FK_ORDER_ID,STATUS)
像这样的订单类
@Entity
@Table(name = "ORDER")
public class Order {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "PK_ORDER_ID", unique = true, nullable = false)
private Long id;
@JoinColumn(name = "FK_ORDER_ID", referencedColumnName = "PK_ORDER_ID")
private Set<OrderStatus> orderStatus;
}
像这样的 OrderStatus 类
@Entity
@Table(name = "ORDER_STATUS")
public class OrderStatus {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "PK_ORDER_STATUS_ID")
private Long id;
@Column(name = "STATUS")
private String status;
public OrderStatus(String status) {
this.status = status;
}
}
某处是其他文件
order.getStatus().add(new OrderStatus("new"));
保存更改的数据库代码是 -
@Transactional(TxType.REQUIRED)
public U merge(U EntityToUpdate) {
return em.merge(EntityToUpdate);
}
它给出以下错误
java.sql.SQLException: (conn:40) Field 'FK_ORDER_ID' doesn't have value
Query is: insert into ORDER_STATUS (STATUS) values (?), parameters ['new']