updating object using saveOrUpdate in Hibernate

Question

I am familiar with Hibernate.I have a question.

Lets say I do session.saveOrUpdate(object). If object contains some 'id'(object identifier), then it means update query will be fired if the object is modified.

I want to know how does Hibernate do that i.e. there could be 'n' number of fields in the object.Does Hibernate check each and every field to know if any field is modified(in this case update query to be fired)?

PSR · Accepted Answer · 2013-05-24 12:06:22Z

2

While using use .saveOrUpdate() it will check if the object has no identifier property and if so it will make it persistent by generating it the identifier and assigning it to session.

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

From Hibernate Docs

answered May 24, 2013 at 12:06

PSR

40.4k43 gold badges115 silver badges154 bronze badges

Sign up to request clarification or add additional context in comments.

7 Comments

Anand Over a year ago

so even if no field is modified, still update query will be fired?

PSR Over a year ago

yes it will fire.Because it will check only the identifier field

Anand Over a year ago

ok..i thought that if no field is modified, update will not be fired. Isn't it a performance issue?? i mean if no change is there in the field, then why to fire update query..

PSR Over a year ago

In my knowledge it only checks the id.You are right in this case .Updation is not necessary.But it is not working like that.You can observe by putting show_sql to true

connectedsoftware Over a year ago

The nHibernate Session keeps track of what needs writing to the database, if you commit a transaction it only updates objects that have changed or inserts new objects.

|

connectedsoftware · Accepted Answer · 2013-05-24 12:07:17Z

0

It checks the field(s) mapped as the identifier for the given object, if the object doesn't have an identifier it calls Save() which INSERTS the object, if it does it calls Update() which UPDATES it

answered May 24, 2013 at 12:07

connectedsoftware

7,0973 gold badges33 silver badges45 bronze badges

Comments

shreyansh jogi · Accepted Answer · 2013-05-24 12:24:04Z

0

Basically in hibernate if you set object with unique identifier any how it is going to update the whole row by calling session.saveOrUpdate();

or if unique identifier not found it insert the data.

answered May 24, 2013 at 12:24

shreyansh jogi

2,10212 silver badges20 bronze badges

Collectives™ on Stack Overflow

updating object using saveOrUpdate in Hibernate

3 Answers 3

7 Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

7 Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related