我需要在外键列中插入一个空值,但是我收到此错误: 有可能吗?
异常
org.springframework.dao.InvalidDataAccessApiUsageException:org.hibernate.TransientPropertyValueException:object引用未保存的瞬态实例 - 在刷新之前保存瞬态实例:com.company.project.model.ConceptoGasto.conceptoGasto - > com.company.project.model.ConceptoGasto;嵌套异常是java.lang.IllegalStateException:org.hibernate.TransientPropertyValueException:object引用未保存的瞬态实例 - 在刷新之前保存瞬态实例:com.company.project.model.ConceptoGasto.conceptoGasto - > com.company.project.model.ConceptoGasto
实体
//----------------------------------------------------------------------
// ENTITY PRIMARY KEY ( BASED ON A SINGLE FIELD )
//----------------------------------------------------------------------
@Id
@GeneratedValue(strategy=GenerationType.AUTO)
@Column(name="id", nullable=false)
private Integer id;
....
@ManyToOne (optional = true)
@JoinColumn(name="idPadre", referencedColumnName="id", nullable=true)
private ConceptoGasto conceptoGasto;
.....
方式
JpaOperation operation = new JpaOperation() {
@Override
public Object execute(EntityManager em) throws PersistenceException {
T managedEntity = em.merge(entityToSave);
//em.refresh(managedEntity);
return managedEntity;
}
} ;