StackOverflow2013

Note that there are some explanatory texts on larger screens.

plurals

POCore Data NSPredicate not returning records between two dates
primarykey
Id
15884250
data
AcceptedAnswerId
15885204
AnswerCount
2
ClosedDate
CommentCount
6
CommunityOwnedDate
CreationDate
2013-04-08T16:25:42.427
FavoriteCount
0
LastActivityDate
2013-04-08T17:27:24.353
LastEditDate
2013-04-08T16:59:24.840
LastEditorUserId
669371
OwnerUserId
669371
ParentId
0
PostTypeId
1
Score
2
ViewCount
1639
LastEditorDisplayName
text
Body
I have a CoreData entity <code>Comment</code> who has a parent entity <code>Measurement</code>. The <code>Measurement</code> entity has a <code>measurementDate</code> attribute. My Core Data database has 200 <code>Comment</code> records in it, each with varying <code>measurementDate</code> values over the last 3 years. I'm trying to get the records where <code>measurementDate</code> is between any two given dates. Firstly, I tried this: <pre><code>//now fetch a record between 12 and 11 months ago NSDate *startDate = [AppGlobals dateByAddingMonths:[NSDate date] withMonths:-12]; NSDate *endDate = [AppGlobals dateByAddingMonths:startDate withMonths:1]; NSPredicate *predicate = [NSPredicate predicateWithFormat:@"(measurementDate >= %@) AND (measurementDate <= %@)", startDate, endDate]; NSFetchRequest *request = [[NSFetchRequest alloc] init]; [request setEntity:[NSEntityDescription entityForName:@"Comment" inManagedObjectContext:self.context]]; [request setPredicate:predicate]; NSError *error = nil; NSArray *results = [self.context executeFetchRequest:request error:&error]; </code></pre> But I got 0 results. So then I tried replacing my predicate with something simpler: <pre><code>NSPredicate *predicate = [NSPredicate predicateWithFormat:@"measurementDate >= %@", startDate]; </code></pre> This should return approximately a third of my results. But actually it returns ALL 200 RECORDS. I've logged out the dates of the objects and it looks like the dates are being completely ignored! What am I doing wrong??? Is it something to do with the Parent Abstract entity <code>Measurement</code> and because I'm fetching from the <code>Comment</code> entity and not the <code>Measurement</code> entity? Is it because I'm using "scalar properties for primitive data types" in my code? Any help greatly appreciated.
Tags
<ios><core-data>
Title
Core Data NSPredicate not returning records between two dates
singulars
PostAcceptedAnswerId
1. PO
 singulars
 PostTypePostTypeId
 PTAnswer
PostParentId
1. This table or related slice is empty.
PostTypePostTypeId
1. PTQuestion
UserLastEditorUserId
1. UStheDuncs
UserOwnerUserId
1. UStheDuncs
plurals
PostLinksPostIdRelatedPostId
1. This table or related slice is empty.
PostLinksRelatedPostIdPostId
1. PL
 singulars
 LinkTypeLinkTypeId
 LTLinked
2. PL
 singulars
 LinkTypeLinkTypeId
 LTLinked
3. PL
 singulars
 LinkTypeLinkTypeId
 LTLinked
PostsAcceptedAnswerId
1. This table or related slice is empty.
PostsParentIdCreationDate
1. PO
 singulars
 PostTypePostTypeId
 PTAnswer
2. PO
 singulars
 PostTypePostTypeId
 PTAnswer
VotesPostIdCreationDate
1. This table or related slice is empty.
CommentsPostId

Querying!

Guidance

A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.