Chris,
thanks for your kind help.
I understand that we have to iterate
over the result, clear the Master.details collection, and fill in all the
details returned by the mapper. Is that correct? Sounds like this should work,
while it is a nasty job. Ain't there a solution how we can tell TopLink that it
shall not invoke the subsequent SQL but just accept the detail entities it just
generated? As it has all that it knows to do the job, this should be possible.
:-)
Another problem is preventing
unwanted database changes. Is there a possibility to actively detach the Master
from the persistence context before clearing ist Master.details collection? If
not, how to prevent the EntityManager from removing the details on the
database?
Thanks
Markus
From: eclipselink-users-bounces@xxxxxxxxxxx
[mailto:eclipselink-users-bounces@xxxxxxxxxxx] On Behalf Of Christopher
Delahunt
Sent: Donnerstag, 24. Juni 2010 15:07
To: EclipseLink User Discussions
Subject: Re: [eclipselink-users] FW: [TopLink Essentials] @SqlResultSetMappingJOINed
details are gettingignored
The problem with custom SQL returning Entities are that they
managed entities, and such that incomplete data built into an entity remains in
the cache (or the full managed object returned if it is already in the
cache). Entities are not data objects that can be left incomplete.
What it seems like you need would be a JPQL constructor type query but for
native SQL.
The results from the query should still give the object pairs you requested,
assuming you have set the query to return the Master and Detail objects from
the join. The application will need to process over the results to get
all the Master->Detail pairings returned from the results, much like it
would for rows when returning raw data.
Best Regards,
Chris
On 24/06/2010 8:49 AM, Markus Karg wrote:
Today for the first time now
I had to use @SqlResultSetMapping. While everything works well there so far,
there still is one issue I would like to solve. Possibly you can help me. :-)
I am executing a typical master-detail JOIN:
SELECT Master.PK_A, Detail.PK_B FROM Master JOIN Detail ON
(Master.PK_A = Detail.FK_A) WHERE Master.X = ? AND Detail.Y = ?
The result is exactly what I expected: A table containing
all details having Y = ? and their corresponding masters.
But actually I want to get not fields but entity instances,
so I added SqlResultSetMapping for Master and Detail, which both are annotated
with @Entity, @Table, @Column, etc.
The result is not exactly what I want get…: The "AND
Detail.Y = ?" has no effect on that details linked with each master.
When iterating over the Master.details collection which was
automatically filled by TopLink behind the scenes thanks to the @OneToMany
relationship, I notice that ALL the master's details are contained - not just
those with actually "Detail.Y = ?" as expected. Looking at the SQL
TopLink does, it is rather clear why: The linked details are not filled from
just my SQL's ResultSet, but actually TopLink executes another (automatically
created) SQL to get ALL details per Master.
This is not what I want.
How to tell TopLink that it shall populate the linked
details of each master with just the rows found in MY OWN SQL but not execute
an unfiltered one?
Thanks!
Markus
____________
Virus checked by G DATA AntiVirus
Version: AVA 21.1046 dated 24.06.2010
Virus news: www.antiviruslab.com
_______________________________________________
eclipselink-users mailing list
eclipselink-users@xxxxxxxxxxx
https://dev.eclipse.org/mailman/listinfo/eclipselink-users
