Hi!Actually, EOKeyValueQualifier("tracks", EOQualifier.QualifierOperatorEquals, NSKeyValueCoding.NullValue) should work just fine.
Please report back if it doesn't. I'd like to know.An alternative - usually used only for more complex cases - would be to use the ExistsInRelationshipQualifier from my Houdah WebObjects frameworks project.
Best, Pierre Bernard Houdah Software s.à r.l. On 4 Jul 2008, at 10:32, Michael Bushkov wrote:
Hi, I have quite simple task, but I don't see any proper solution. The task is as follows: I have 2 entities - Song and Track. Song has a one-to-many relationship to Track (Song->tracks). And I need to fetch all songs which have no tracks. That's all - plain and simple. I've looked through the list of available qualifiers and even started to write one by myself, but it looks like an overkill for such a simple task. The straightforward solution, that I see is to cache number of tracks in Song entity (make a Song->tracksNumber field). But it looks like modifying model for implementation purposes (this however can be very effective on large datasets, because such database structure doesn't require using subqueries to find songs with no tracks). Any suggestions are greatly appreciated ) -- With best regards, Michael Bushkov _______________________________________________ Do not post admin requests to the list. They will be ignored. Webobjects-dev mailing list ([email protected]) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/webobjects-dev/webobjects-dev%40houdah.com This email sent to [EMAIL PROTECTED]
--- Pierre Bernard http://www.bernard-web.com/pierre http://www.houdah.com
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