更新空子集合引发错误

Question

class Attribute{
--- other entity def

  @OneToMany(fetch=FetchType.LAZY, orphanRemoval=true, cascade=CascadeType.ALL)
  @JoinColumn(name="ATTRDEFID", nullable=false, insertable=false , updatable=false)
  @OrderBy("IDX")
  private List<Constraint> constraints = new ArrayList<Constraint>();  
--- other entity def
}

At a time of update/save attribute, contraint is null. This error throw in case of update only.

org.springframework.orm.jpa.JpaSystemException: A collection with cascade="all-delete-orphan" was no longer referenced by the owning entity instance: com.revitas.cm.persistence.term.Attribute.constraints; nested exception is org.hibernate.HibernateException: A collection with cascade="all-delete-orphan" was no longer referenced by the owning entity instance: com.revitas.cm.persistence.term.Attribute.constraints

When I set empty collection instead of null, it saved successfully.

if(attribute.getConstraints()==null){
        attribute.setConstraints(new ArrayList<>());
    }

Why such error thrown? why is it solved through empty collection? does it correct solution or not? I do googling related to this . but not getting proper idea why such issue.

Answer 1

The issue is with attribute which contains null constraints and called merge operation for update.

As per this link https://hibernate.atlassian.net/browse/HHH-7726 provided by hibernate.

removing children through parent.setChildren(null) and then committing the change using session.merge(parent) throws org.hibernate.HibernateException: A collection with cascade="all-delete-orphan" was no longer referenced by the owning entity instance: Parent.children

Either need to set empty collection or not passed value if json. Json input will be two ways:

1) []

2) Not passed element atall.