Re: CoreData "in" predicate
Re: CoreData "in" predicate
- Subject: Re: CoreData "in" predicate
- From: Rick Mann <email@hidden>
- Date: Sun, 2 May 2010 15:12:15 -0700
Thanks, everyone, for telling me about "self."
On May 2, 2010, at 14:53:09, Frederick Reimer wrote:
> Wrong assumption; you would actually use "SELF" in a format string, as it is a reserved word. So @"SELF IN %@"
>
> I think...
>
>
> Fred Reimer, CCIE 23812 CISSP 107125
> mailto:email@hidden
>
>
>
> On May 2, 2010, at 4:32 PM, Frederick Reimer wrote:
>
>> Unfortunately, there is nothing for the NSPredicate class to go on to assume what object you are talking about. predicateWithFormat is a class method/selector/function. What object is it supposed to assume you mean if one is not supplied?
>>
>> Dan Rowley sent me an email saying you may be able to use "self." So, I assume this means:
>>
>> NSPredicate *pred = [NSPredicate predicateWithFormat: @"%K in %@", self, favoriteMissions];
>>
>> HTH,
>>
>> On May 2, 2010, at 9:03 AM, Rick Mann wrote:
>>
>>> I saw that, I had hoped that by not specifying an attribute, it would mean the object itself, not an attribute on the object.
>>>
>>>
>>> On May 2, 2010, at 05:58:39, Frederick Reimer wrote:
>>>
>>>> The manuals for this give the following example:
>>>>
>>>> NSPredicate *inPredicate =
>>>> [NSPredicate predicateWithFormat: @"attribute IN %@", aCollection];
>>>>
>>>> It looks like you are missing the attribute... If attribute can vary, you can use a %K and a NSString value representing the attribute name (it is not automatically enclosed in quotes as %@ values are).
>>>>
>>>> HTH,
>>>>
>>>> Fred
>>>> On May 2, 2010, at 8:27 AM, Rick Mann wrote:
>>>>
>>>>> Hi.
>>>>>
>>>>> I have two entities: Mission and Favorite. Favorite has a single relation to Mission. I need to fetch all Mission objects that exist in Favorite. I'm using an NSFetchResultsController.
>>>>>
>>>>> I created an array with all the Mission objects found in the Favorite entity. Then I tried to create a predicate like this:
>>>>>
>>>>> NSPredicate* pred = [NSPredicate predicateWithFormat: @"in %@", favoriteMissions];
>>>>>
>>>>> and use that on a fetch of Mission objects. But it complains that it can't parse that format string.
>>>>>
>>>>> Clearly, this approach isn't going to work. I could store the Mission's key in the Favorite table instead, but that's less elegant. Might be the only way to go.
>>>>>
>>>>> Any suggestions?
>>>>>
>>>>> tia,
>>>>> Rick
>>>>>
>>>>> _______________________________________________
>>>>>
>>>>> Cocoa-dev mailing list (email@hidden)
>>>>>
>>>>> Please do not post admin requests or moderator comments to the list.
>>>>> Contact the moderators at cocoa-dev-admins(at)lists.apple.com
>>>>>
>>>>> Help/Unsubscribe/Update your Subscription:
>>>>>
>>>>> This email sent to email@hidden
>>>>>
>>>>
>>>
>>>
>>
>> Fred Reimer, CCIE 23812 CISSP 107125
>> mailto:email@hidden
>>
>>
>>
>
_______________________________________________
Cocoa-dev mailing list (email@hidden)
Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden