Hibernate 异常：“@OneToOne or @ManyToOne on XXX references an unknown entity: XXX”

使用Hibernate进行自关联时@ManyToOne 定义的类型Order是接口，需要显示指定实现类

@ManyToOne(fetch=FetchType.LAZY, targetEntity = OrderImpl.class, cascade = CascadeType.MERGE)  
@JoinColumn(name="PARENT_ORDER_ID")  
private Order parent;