Updating counters through Hibernate - sql

Question

This is an extremely common situation, so I'm expecting a good solution. Basically we need to update counters in our tables. As an example a web page visit:
Web_Page
--------
Id
Url
Visit_Count
So in hibernate, we might have this code:
webPage.setVisitCount(webPage.getVisitCount()+1);
The problem there is reads in mysql by default don't pay attention to transactions. So a highly trafficked webpage will have inaccurate counts.
The way I'm used to doing this type of thing is simply call:
update Web_Page set Visit_Count=Visit_Count+1 where Id=12345;
I guess my question is, how do I do that in Hibernate? And secondly, how can I do an update like this in Hibernate which is a bit more complex?
update Web_Page wp set wp.Visit_Count=(select stats.Visits from Statistics stats where stats.Web_Page_Id=wp.Id) + 1 where Id=12345;

Answer 1

The problem there is reads in mysql by default don't pay attention to transactions. So a highly trafficked webpage will have inaccurate counts.
Indeed. I would use a DML style operation here (see chapter 13.4. DML-style operations):
Session session = sessionFactory.openSession();
Transaction tx = session.beginTransaction();
String hqlUpdate = "update webPage wp set wp.visitCount = wp.visitCount + 1 where wp.id = :id";
int updatedEntities = s.createQuery( hqlUpdate )
.setLong( "newName", 1234l )
.executeUpdate();
tx.commit();
session.close();
Which should result in
update Web_Page set Visit_Count=Visit_Count+1 where Id=12345;
And secondly, how can I do an update like this in Hibernate which is a bit more complex?
Hmm... I'm tempted to say "you're screwed"... need to think more about this.

Answer 2

A stored procedure offers several benefits:
In case the schema changes, the code need not change if it were call increment($id)
Concurrency issues can be localized.
Faster execution in many cases.
A possible implementation is:
create procedure increment (IN id integer)
begin
update web_page
set visit_count = visit_count + 1
where `id` = id;
end