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POTableview with sections per day (with Core Data)
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  1. POTableview with sections per day (with Core Data)
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    copied!<p>I have quite an ordinary RSS-reader type App. The objects in the Core Data have a pubDate attribute which is the exact date + time of publishing. Using this for sections gives every article its own section.</p> <p>Therefore I added a transient attribute:</p> <pre><code>@dynamic sectionDay; -(NSString *) sectionDay { // Get the date, and convert it to the day (counld probably be done a bit more scientific!) NSDateFormatter* formatter = [[[NSDateFormatter alloc] init] autorelease]; //Set the required date format [formatter setDateStyle:NSDateFormatterLongStyle]; // Set the values; NSString *dateString = [formatter stringFromDate:self.pubDate]; return dateString; } </code></pre> <p>Then in the FetchedResultsController I added sectionDay as the sectionNameKeyPath</p> <pre><code> // Edit the sort key as appropriate. NSSortDescriptor *sortDescriptor = [[[NSSortDescriptor alloc] initWithKey:@"pubDay" ascending:NO] autorelease]; NSArray *sortDescriptors = [NSArray arrayWithObject:sortDescriptor]; NSFetchedResultsController *aFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:[self managedObjectContext] sectionNameKeyPath:@"sectionDay" cacheName:nil]; </code></pre> <p>The problem is that I get an "ojbc_exception_throw" on NSFetchedResultsController PerformFetch:</p> <p>*</p> <pre><code>#0 0x012165a8 in objc_exception_throw #1 0x00eba676 in -[NSSQLGenerator newSQLStatementForFetchRequest:ignoreInheritance:countOnly:nestingLevel:] #2 0x00df2a78 in -[NSSQLAdapter _newSelectStatementWithFetchRequest:ignoreInheritance:] #3 0x00df2881 in -[NSSQLAdapter newSelectStatementWithFetchRequest:] #4 0x00df272e in -[NSSQLCore newRowsForFetchPlan:] #5 0x00df1ab5 in -[NSSQLCore objectsForFetchRequest:inContext:] #6 0x00df166e in -[NSSQLCore executeRequest:withContext:error:] #7 0x00ea10ec in -[NSPersistentStoreCoordinator executeRequest:withContext:error:] #8 0x00dee807 in -[NSManagedObjectContext executeFetchRequest:error:] #9 0x00ed2c10 in -[NSFetchedResultsController performFetch:] #10 0x0000456e in -[ArticleController getArticles] at ArticleController.m:92 </code></pre> <p>*</p> <p>Any suggestions what I do wrong?</p>
 

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