nil properties in Fetch Requests
nil properties in Fetch Requests
- Subject: nil properties in Fetch Requests
- From: Óscar Morales Vivó <email@hidden>
- Date: Mon, 11 Jul 2005 09:33:14 -0400
Reposting since I think it got lost in the shuffle yet shouldn't be a
hard one to answer for the right people:
I've had time again to dedicate some time to Core Data, and have hit
another hitch. Let me explain:
I have a fetch request like the following:
isMale == 1 AND dateOfBirth < $CALLERBIRTHDAY AND dateOfDeath >=
$CALLERBIRTHDAY
Where isMale is a non-optional boolean property, and both dateOfBirth
and dateOfDeath are optional date properties.
I know I cannot instantiate $CALLERBIRTHDAY with nil. In those cases
where I find it, I can substitute it for [NSDate distantPast] and
[NSDate distantFuture] as appropriate.
However I don't know how and if the predicate will work if
dateOfBirth and/or dateOfDeath haven't been set for any of the
entities that go through it. Depending on the behavior I'll have to
pretty much forget about using fetch requests for my needs and go
through code, which kind of defeats the purpose of the fetch requests
in the first place.
I've also noticed I could sidestep the problem completely if I set
the default value for the "dateOfBirth" property to [NSDate
distantPast] and the one for "dateOfDeath" as [NSDate distantFuture].
The Xcode 2.1 model editor won't allow me to do so (worth filing a
bug?), but I could set them by code as I've read in the documentation.
The only problem is that I don't know at what point I should set them
before the object model starts being used, nor from which object
(custom document class?). I know this has been discussed elsewhere
but I'm having problems finding it so pointers to it will be greatly
appreciated.
Any knowledge or pointers to it will be appreciated.
Óscar Morales Vivó.
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Cocoa-dev mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden