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unidirectional ManyToOne nullable relation

  Asked By: Jada    Date: Oct 31    Category: Java    Views: 1449

There is a question; I would be tank full if anybody helps to solve it.
There is an unidirectional Many to one relation that can be null, I tried to use @ManyToOne(optional=true) or @JoinColumn(nullable=true) annotations or even both at the same time in my entity class.

private Contract contract;

Although I used these annotations, still it does not work and giving me following error:
During synchronization a new object was found through a relationship that was not marked cascade PERSIST: null.



3 Answers Found

Answer #1    Answered By: Skye Hughes     Answered On: Oct 31

Try this:

@ManyToOne(optional=true, cascade={PERSIST, MERGE})
@JoinTable(name="CONTRACT_TABLE", joinColumn=@JoinColumn(name="FOREIGN_KEY_IN_CONT_TABLE"))
private Contract contract

As you said this is a unidirectional relationship so you need to persist or merge the other side of this relationship in a way, to do this you have to use 'cascade' attribute as above

Answer #2    Answered By: Funsani Chalthoum     Answered On: Oct 31

Thank you for your replying, I had been tried your solution but it made me in trouble, when I leave FK field blank (null)and set cascade=PERSIST, when it persist,it will persist a row with all column value (except id) fill with null  for other side of relationship.

Answer #3    Answered By: Randall Franklin     Answered On: Oct 31

Ok that's good news, please show us how could you resolve the problem

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