OQL syntax, was: RE: OJB

[ol...@ppi.de]

Hello,

> -----Original Message-----
> From: Thomas Mahler [mailto:thma@apache.org]
> 
> POET (www.poet.com)

I am new to OJB, but I know about Poet (or rather: FastObjects,
as the product is called now).

> > OJB - the best example is this from the provided link
> > 
> > SELECT x FROM persons x WHERE x.name = "Pat" 
> > 
> > OJB OQL does not support the aliasing (persons x) so the 
> above has to be
> > written as
> > 
> > SELECT x FROM persons WHERE name = "Pat"
> > 

In FastObjects-OQL syntax, this can be written as:

SELECT x FROM personsExtent AS X WHERE x.name = "Pat"

You can also do things like:

SELECT x.spouse.name FROM personsExtent AS X WHERE x.name = "Pat"

to get the names of people married to a "Pat".  (In case
of FastObjects as a String-array, not a DCollection)

Can you do this in OJB-OQL, too?

Apart from the OQL-syntax, I agree that Poet has a fairly
standard compliant API and documentation.

Oliver

-- 
  Dr. Oliver Matz
  ppi Media GmbH
  Deliusstraße 10
  D-24114 Kiel
  phone		+49 (0) 43 1-53 53-422
  fax     	+49 (0) 43 1-53 53-2 22
  email	mailto:oliver.matz@ppi.de
  web	www.ppi.de

Re: OQL syntax, was: RE: OJB

["J. Russell Smyth" <dr...@cox.net>]

> 
> SELECT x.spouse.name FROM personsExtent AS X WHERE x.name = "Pat"
> 
> to get the names of people married to a "Pat".  (In case
> of FastObjects as a String-array, not a DCollection)
> 
> Can you do this in OJB-OQL, too?

you should be able to do this as:

SELECT x.spouse.name FROM personsExtent WHERE name = "Pat"

but I will not guarantee it! One thing our experience has shown us
is that since OJB-OQL does not provide aliases (person x - x in person -
pserson as x) something funny happens - if OJB recongnizes x.spouse.name
as attributes on person objects, then all will be ok. However, if not,
it will treat the whole x.spouse.name as a single string (like "select
obj from persons where...") and will return the objects you query, not
the requested property.
 
> 
> Apart from the OQL-syntax, I agree that Poet has a fairly
> standard compliant API and documentation.
> 
> Oliver
> 
> -- 
>   Dr. Oliver Matz
>   ppi Media GmbH
>   Deliusstraße 10
>   D-24114 Kiel
>   phone		+49 (0) 43 1-53 53-422
>   fax     	+49 (0) 43 1-53 53-2 22
>   email	mailto:oliver.matz@ppi.de
>   web	www.ppi.de
> 
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> 

addGroupBy - Please help me!!!!!!!!!

[Dhamodharan P <dh...@yahoo.co.uk>]

Dear  Thomas,

                    I am trying to use "addGroupBy" method in my project,but it isthroughing following exception:

java.lang.ClassCastException: [Ljava.lang.Object;

 at com.mxic.tdsplus.TestODMGServices.main(TestODMGServices.java:40)


Just go through my code below and check the while loop condition, if it is wrong just guide me.

 

package com.mxic.tdsplus;
import java.util.*;
import com.mxic.tdsplus.leadscan.*;
import org.apache.ojb.broker.query.*;
import org.apache.ojb.broker.PersistenceBroker;
import org.apache.ojb.broker.PersistenceBrokerFactory;


public class TestODMGServices
{

  public TestODMGServices() {
  }

 public static void main(String[] dhamu)
 {
   java.util.Iterator iter=null;
      try
        {
       
      PersistenceBroker broker=PersistenceBrokerFactory.defaultPersistenceBroker();

      Criteria crit1 = new Criteria();
      ReportQueryByCriteria q = QueryFactory.newReportQuery(LotSummaryForm.class, crit1);
      q.setColumns(new String[] {"LOT_NO"});
      crit1.addGroupBy("LOT_NO");
      iter = broker.getReportQueryIteratorByQuery(q);
     
             while(iter.hasNext())
             {
             LotSummaryForm lot_item_form=(LotSummaryForm)iter.next();
             System.out.println("Lot_no = "+lot_item_form.getLot_no());
             }
             broker.close();

       }
        catch (Exception ex)
        {
           ex.printStackTrace();
           System.out.println(ex.getMessage());
        }

    }
 }


 

Thanks in Advance

Dhamu



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