nhibernate 'save' -> 'get' problem

Question

HEllo,

I'm using nhibernate and have problems regarding user registration on my site.

When user wants to register I create new user record in the database and immidiatelly after that the system is logging the user in.

Well here lies the problem... When creating user record I'm using

NHibernateSession.Save(entity); //does not saves user object immediately to the database. It's kept in the session.

And when I want to log the user in, i load the user by his user name, and then I get null user object.

Why am I getting a null object and how can I make it work?

Thanks

Answer 1

If your Save and Get are done from different sessions then the Get will return null because the object only exists in the other sessions internal cache until it is flushed.

I'm not sure if an L2 cache would make a difference (I don't if L2 cache is written at Save or Flush).

Answer 2

Ok, I just tested this :

        ISession session = s.CreateSession();

  User user = new User();

  user.Number = 122;
  user.UserName = "u";
  user.Id = 1;

  session.Save(user);
  User user1 = session.CreateCriteria<User>().Add(Restrictions.Eq("UserName", "u")).UniqueResult<User>();

  session.Flush();

First the Select is being executed from the CreateCriteria and then on Flush the insert. So that's why it's not finding anything.

I also tested with Get<User>(1) and it returns the entity passed to the Save method - no query is executed.

Still - why query the database since you have the entity right there ?

Also, you say you use Get and then say you want to load by the UserName - is the UserName the primary key ? Get tries to load by the primary key.