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Help about associations/collections

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larini

Post subject: Help about associations/collections

Posted: Tue Sep 11, 2007 4:09 pm

Newbie

Joined: Fri Aug 17, 2007 10:06 am
Posts: 11

The problem: I want to avoid N+1 selects

So, I try the following in my case:

Code:

 List list = Sistema.getSession()  
 .createCriteria(Note.class)  
     .add(Restrictions.eq("dateIn", today))  
 .setFetchMode("items", FetchMode.JOIN)  
 .list();     

and change my Note.hbm to use fetch="subselect" in items.
This approach is good, it brings me all items of all notes at same time.

But I need a little thing, I need all notes but only the items with "quantity>10"

I don´t know how to do this..
Thanks for any help.

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larini

Post subject:

Posted: Tue Sep 11, 2007 5:00 pm

Newbie

Joined: Fri Aug 17, 2007 10:06 am
Posts: 11

I change my example to:

Code:

 List list = Sistema.getSession() 
 .createCriteria(Note.class) 
     .add(Restrictions.eq("dateIn", today)) 
  .createCriteria("item", JoinFragment.LEFT_OUTER_JOIN)
     .add(Restrictions.ge("quantity", new Integer(10)))
 .list();      

but the "quantity > 10 " is writen in the "where" clause:

Code:

select ...
 left outer join ...
where
  quantity>10

when I want this in the left join clause:

Code:

select ...
  left outer join ... (.. and quantity>10)

[/code]

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larini

Post subject:

Posted: Wed Sep 12, 2007 12:51 pm

Newbie

Joined: Fri Aug 17, 2007 10:06 am
Posts: 11

Code:

      Query q = Sistema.getSession().createQuery(
            "from GrsBeneficiario b "+
            "left join b.grsGuia g with g.tipoguia=1 "+
            "left join g.grsGuiaEvento e with e.evento in (select gee.evento from GrsGrupoeventosEvento gee) "+
            "where b.codigo >= :codigo");
      q.setString("codigo", "00000300000000009595");
      return q.list();

this code gives the error:

with-clause referenced two different from-clause elements [from previnne.GrsBeneficiario b left join b.grsGuia g with g.tipoguia=1 left join g.grsGuiaEvento e with e.evento in (select gee.evento from previnne.GrsGrupoeventosEvento gee) where b.codigo >= :codigo]

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larini

Post subject:

Posted: Wed Sep 12, 2007 1:49 pm

Newbie

Joined: Fri Aug 17, 2007 10:06 am
Posts: 11

Hibernate is dead or this is a huge vacation?

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