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Posted to ojb-user@db.apache.org by Info <in...@crestax.ca> on 2004/04/23 20:32:05 UTC

Code in two table join

Hello,

I tried the following code to select a join, but get error:


            Criteria crit = new Criteria();
            crit.addEqualToColumn("A.xxx", "B.xxx");
            ReportQueryByCriteria q = 
QueryFactory.newReportQuery(A.class, crit);
            
            q.setAttributes(new String[] {"A.xxx", "A.yyy", "B.zzz" });

            Iterator it = broker.getReportQueryIteratorByQuery(q);

( In the case,  for string "A.xxx" or "B.zzz", what name should I use as 
A or B? The physical table name or class name represented or other name?)
SQL statement:

SELECT A.xxx, A.yyy, B.zzz
FROM A JOIN B
ON A.xxx = B.xxx

Please help!

Thanks!
Wallace


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Re: Code in two table join

Posted by Jakob Braeuchi <jb...@gmx.ch>.
hi wallace,

it's not necessary to join manually, ojb will do it for you:

Criteria crit = new Criteria();
ReportQueryByCriteria q = QueryFactory.newReportQuery(A.class, crit);
q.setAttributes(new String[] {"xxx", "yyy", "rel_b.zzz" });

Iterator it = broker.getReportQueryIteratorByQuery(q);

there must be a relationship-definition from class A to B named 'rel_b' in the 
repository.

jakob

Info wrote:

> Hello,
> 
> I tried the following code to select a join, but get error:
> 
> 
>            Criteria crit = new Criteria();
>            crit.addEqualToColumn("A.xxx", "B.xxx");
>            ReportQueryByCriteria q = 
> QueryFactory.newReportQuery(A.class, crit);
>                       q.setAttributes(new String[] {"A.xxx", "A.yyy", 
> "B.zzz" });
> 
>            Iterator it = broker.getReportQueryIteratorByQuery(q);
> 
> ( In the case,  for string "A.xxx" or "B.zzz", what name should I use as 
> A or B? The physical table name or class name represented or other name?)
> SQL statement:
> 
> SELECT A.xxx, A.yyy, B.zzz
> FROM A JOIN B
> ON A.xxx = B.xxx
> 
> Please help!
> 
> Thanks!
> Wallace
> 
> 
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: ojb-user-unsubscribe@db.apache.org
> For additional commands, e-mail: ojb-user-help@db.apache.org
> 
> 

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