hi again,
I think this is indeed the reason. In my log files those selects almost
always occur right after prefetch queries. And in the few cases they
don't, it may just be that there was no non-null FK to prefetch.
Method ReferencePrefetcher#buildPrefetchQueries already checks for isNull(fkValues) so
#associateBatched should probably do the same.
Gerhard
Jakob Braeuchi <[EMAIL PROTECTED]>
15.10.2003 17:17
Bitte antworten an "OJB Users List"
An: OJB Users List <[EMAIL PROTECTED]>
Kopie:
Thema: Re: Antwort: RE: How to map optional 1:1 relationship
hi carl,gerhard,
your right, fkValues may be null and thus a query will be fired.
can you confirm this gerhard ?
jakob
Boyes, Carl wrote:
> Hi Jakob, Gerhard
>
> In ReferencePrefetcher#associateBatched:
>
> ...
> while (iter.hasNext())
> {
> owner = iter.next();
> fkValues = ord.getForeignKeyValues(owner,cld);
> id = new Identity(null, topLevelClass, fkValues);
> relatedObject = pb.getObjectByIdentity(id);
> field.set(owner, relatedObject);
> }
> ...
>
> Should this also be ensuring a non null foreign key value?
>
> Carl.
>
>
>
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
> Sent: Wednesday, October 15, 2003 3:59 PM
> To: OJB Users List
> Subject: Re: Antwort: RE: How to map optional 1:1 relationship
>
>
> Hi Jakob,
>
> I just checked and you are right.
>
> Nevertheless I find a lot of statements like SELECT ... FROM ... WHERE
> id='' in my P6Spy logs, where id is a not nullable primary key. I was
> assuming these were generated from resolving references with FK=null,
but
> it turns out this is wrong. Looks like I'll have to do a little more
> research to find the reason for these selects...
>
> Regards,
> Gerhard
>
>
>
>
>
> Jakob Braeuchi <[EMAIL PROTECTED]>
> 15.10.2003 16:10
> Bitte antworten an "OJB Users List"
>
>
> An: OJB Users List <[EMAIL PROTECTED]>
> Kopie:
> Thema: Re: Antwort: RE: How to map optional 1:1 relationship
>
>
> hi gerhard,
>
> imo this is already implemented. see
> PersistenceBrokerImpl#getReferencedObject:
>
> ...
> // BRJ: check if we have non null pk values
> // TBD we should also check primitives
> // to avoid creation of unmaterializable proxies
> for (int i = 0; i < pkVals.length; i++)
> {
> if (pkVals[i] != null)
> {
> allPkNull = false;
> break;
> }
> }
> // BRJ: if all pk values are null there's no referenced object
> if (allPkNull)
> {
> return null;
> }
> ...
>
>
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