Hi Paul,
as far as I know there is no possibility to use inner joins with OQL. An alternativ may be to use SQL passthrough queries with the:
CALL <sql-select-query> AS <classname>
syntax.
If you face performance problems you may have a look at:
http://docs.codehaus.org/display/CASTOR/Best+practis+to+use+CastorJDO
Even if this document is not clearly arranged it contains lots of interessting points to take into account if performance is an issue for you.
Ralf
PAUL CHAN NCSI HK NCS schrieb:
Does Castor support inner join to retrieve the one to many records now and how? Now we face the performance issue that if there are too many record on child table
-----Original Message----- From: Werner Guttmann [mailto:[EMAIL PROTECTED] Sent: Thursday, May 05, 2005 8:35 PM To: [email protected] Subject: Re: [castor-user] Does Castor JDO use Out Join to retrieve One-To-Many table record s?
Paul,
yes, Castor currently uses outer joins to fetch objects associated as part
of a 1:M relation. This is done so that all records from the 'one' leg of the association are returned when there are no
associated objects on the 'M' side.
Regards Werner
On Thu, 5 May 2005 19:11:40 +0800, PAUL CHAN NCSI HK NCS wrote:
Hi All,
Does Castor JDO use Out Join to retrieve One-To-Many table records? Can Castor JDO use Inner Join to retrieve One-To-Many table records?
I found some method stated at javadoc
http://www.jdocs.com/castor/0.9.5.3/api/org/exolab/castor/persist/spi/Query
Expression.html addInnerJoin method?? addOuterJoin method?? Does it mean that Castor JDO can user inner join to retrieve one-to-many table records?
Paul
