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Faq does not appead to complet ans. count of query results?

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matt_p11

Post subject: Faq does not appead to complet ans. count of query results?

Posted: Thu Jul 22, 2004 3:52 pm

Beginner

Joined: Mon Mar 22, 2004 9:37 am
Posts: 22
Location: Willow Grove, PA

I don't want to be annoying.

However, I have looked through the faq.

I have found

Code:

( (Integer) s.createFilter( collection, "select count(*)" ).iterate().next() ).intValue()

However, how does this help for named queries?

I am using the following code with "name" is supplied parameter of the named query we want to execute.

Code:

   public ResultInfo getPagedResults(final String name, final int pageSize, final int currentPage) throws ServiceException{
      
      return (ResultInfo) getHibernateTemplate().execute(new HibernateCallback() {
         public Object doInHibernate(Session session) throws HibernateException {
            Query q = session.getNamedQuery(name);
            
            
            int resultCount = ((Integer) session.createFilter( q.list(), "select count(*)" ).iterate().next()).intValue();
            q.setCacheable(true);
            q.setMaxResults(pageSize);
            q.setFirstResult(currentPage * pageSize);
            
            ResultInfo ri = new ResultInfo(q.list(), resultCount);
            return ri;      
         }
      });
         
   }

I am afraid that the q.list() below already is returning a full list from the database.

Code:

   int resultCount = ((Integer) session.createFilter( q.list(), "select count(*)" ).iterate().next()).intValue();

Is there a solution that will work for any named query(and mysql 4.0ish, ie. no subselects)

Thank you,

Matthew Payne[/code]

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mbatsis

Post subject:

Posted: Wed Sep 08, 2004 10:11 am

Beginner

Joined: Wed Sep 17, 2003 10:43 am
Posts: 48

Can someone please verify on whether the full list is *loaded* from the database in the last line of code posted by Matthew?

I was very suprised when i found out that

Code:

( (Integer) s.createFilter( collection, "select count(*)" ).iterate().next() ).intValue();

does not initialize the collection, so I was hoping this could also work.

Thanks!

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mbatsis

Post subject: Counting query results

Posted: Wed Sep 08, 2004 10:46 am

Beginner

Joined: Wed Sep 17, 2003 10:43 am
Posts: 48

... which doesn't seem to work since filters are only applicable to persistent collections :-(

Supposing you have a Query object (with all parameters set) and a Session object, whats the more efficient way to count the results if you want to page? All I could think of was

Code:

            query.setCacheable(true);
            int totalResults = query.list().size(); 
            // now page
            query.setFirstResult((pageNumber-1) * pageSize);
            query.setMaxResults(pageSize + 1);
            List page = query.list();

isn't there a better way?

Thanks,

Manos

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