Hibernate onetomany not updating
This Hibernate basics tutorial shows you three different ways to remove an entity from the datastore. Suppose that we have the following entity relationship (one-to-many): A category can contain one or many products. I knew that I was the only one modifying this row and the version had not changed.After this I decided to implement an equals() and hash Code() for every single entity attached to the the object I was updating.You only need to care about transient objects in most of cases. It updates the database with values from a detached entity.In this tutorial, I am discussing few thoughts around Sometimes we face situation where we application database is modified with some external application/agent and thus corresponding hibernate entity in your application actually becomes out of sync with it’s database representation i.e. Refresh method was updating the entity with latest database information. Merging is performed when you desire to have a detached entity changed to persistent state again, with the detached entity’s changes migrated to (or overriding) the database.
The course object might also include a list of students.However in complex situations it is not always simple to override equals() and hash Code().Lets start with simple example of a Hibernate entity.It’s much easier to start Hibernate with a clean database and ability to build your entities to JPA standards but sometimes that is not the case.
There we learned that in most of the cases, you will not even need those methods as hibernate manages the updates on persistent entities automatically.
The first thing we should remember is not to include id or last update date as these are generated by Hibernate.