错误：对象引用了未保存的瞬态实例

Question

I am using Hibernate, and I got the following error:

org.hibernate.TransientObjectException: object references an unsaved transient instance - save the transient instance before flushing: db.Concern

I created an object of the Concern entity, where I did the following:

@OneToOne(cascade = CascadeType.ALL, fetch = FetchType.LAZY)
@JoinColumn(name = "concernId")
private Concern concern;

Answer 1

When using Hibernate or any other JPA provider, setting cascade = CascadeType.ALL causes persist and update and other operations being cascaded down to child relationships.

In addition by default @OneToOne relationships are FetchType.Eager . So you can either save concern explicitly or you can remove fetch = FetchType.LAZY from the annotation .

You are probably saving some other object when this error is thrown. So before saving that object save the concern object and then the other object.