使用相同的对象多次调用休眠的 save() 方法会在数据库中插入新记录吗？

Question

for(int index=0; index<10; index++) {
   Session session = hibernateTemplate.getSessionFactory().openSession();
   session.save(object);
}

Does this code store the passed object in save(object) in DB 10 times or it will be overridden every time?

Answer 1

It depends on the object's state.

If you create a new object each time, new object is in the transient state: it is not mapped to a database record and not managed by any persistence context. So, calling Hibernate's save() method will create a new record in the database.

But if you call save() method with a managed object which is already attached to the current persistence context and mapped to a database record: the same object will be updated.

Answer 2

 save method in hibernate:
 *Persist the given transient instance, first assigning a generated identifier. (Or
 using the current value of the identifier property if the assigned
 generator is used.) This operation cascades to associated instances if the
 association is mapped with cascade="save-update"
 Accept parameters :@param object a transient instance of a persistent class
 Return Prameters : @return the generated identifier*

In summary, the save() method saves records into the database by INSERT SQL query, Generates a new identifier, and returns the Serializable identifier back. So you will have 10 Object record in your database with different Ids

 Read more: https://javarevisited.blogspot.com/2012/09/difference-hibernate-save-vs-persist-and-saveOrUpdate.html#ixzz6F8Hiy8fF

 Hope it helps.