使用Hibernate创建createCriteria和beginTransaction的顺序有什么不同？

Question

Just wondering is there any difference when I beginTransaction [org.hibernate] before or after creating Criteria/Query etc.?

example 1:

...
Transaction tx= session.beginTransaction();
Criteria c = session.createCriteria(class);
result = c.uniqueResult();
tx.commit();
...

example 2:

...
Criteria c = session.createCriteria(class);
Transaction tx= session.beginTransaction();
result = c.uniqueResult();
tx.commit();
...

Thanks.

Answer 1

Creating a transaction before executing crteria is enough.

There will be no difference of that line.All you need is a trnasaction before you are executing the criteria.

Answer 2

There is no difference as transaction matters when you actually working on the database. Creating criteria will not make any change to the database until you don't execute it. You may even take creation of criteria out of transactions.