休眠具有不同值的同一对象

Question

I have one class with specific columns, say

Class A
{
    private String A;
    private String B;
    private String C;

    // Getter Setter of respectives
}

Now what happened I have same value of column A and column B only column C 's value change. So I do something like below

A a = new A();
a.setA(..);
a.setB(..);

for(i=0;i<length;i++){
     a.setC(..);

     getHibernateTemplate.saveOrUpdate(a);

     // or something like this
     // A a1 = new A();
     // a1 = a;
     // a1. setC(..);
     // getHibernateTemplate.saveOrUpdate(a1);

}

My issue is it does not store length number of records, it only updates that single record.

I know the reason that hibernate access it as persistent object and even if I change value and again save it will update existing record and it can be resolve by taking new object every time and setting it all values . But I don't want it, is there any way to tell hibernate to save that record instead of updating?

Answer 1

You haven't described actual entity details. If you want to save entity with the same values, set the identifier property as null .

From Documentation -

saveOrUpdate()

• if the object is already persistent in this session, do nothing
• if another object associated with the session has the same identifier, throw an exception
• if the object has no identifier property, save() it
• if the object's identifier has the value assigned to a newly instantiated object, save() it
• if the object is versioned by a or , and the version property value is the same value assigned to a newly instantiated object, save() it
• otherwise update() the object

saveOrUpdateAll()

• Save or update all given persistent instances, according to its id (matching the configured "unsaved-value"?). Associates the instances with the current Hibernate Session.

[ If it works, can try this for your other query ]

---

Edit : It's mine oversight, I haven't checked your code carefully. You have defined object A outside for loop, therefore the same object was being updated in each iteration. Try the below code, might help.

for(i=0;i<length;i++){
A a = new A();  //-- Create new object for each iteration
a.setA(..);
a.setB(..);
a.setC(..);

getHibernateTemplate.saveOrUpdate(a);
}

Answer 2

是的，尝试使用save(a)而不是saveOrUpdate(a)

getHibernateTemplate.save(a);  //each time a new object saves.