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POLoop through array & fetch data from Core-Data
 

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    <p>I've got an array of 200 numbers (item ids) and I want to get some data from core data for each item using its item id. I am assuming the only way to do so is to query core data within a loop performing the fetchRequest in each iteration and adding the results to a mutable array. This seems like a memory hog and looping over 200 items may not be the best way of getting that data I need.</p> <p>The destination for all this data is a table so I'd like to use an NSFetchedResultsController, however, that might be asking too much.</p> <p>What is the best way to retrieve data from core data when you have several hundred items for which you wish to query?</p> <p>Illustrative code examples would be most appreciated. </p> <p>Here is my code:</p> <pre><code>- (NSFetchedResultsController *)fetchedResultsController { if (_fetchedResultsController != nil) { return _fetchedResultsController; } NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init]; NSEntityDescription *entity = [NSEntityDescription entityForName:@"Shows" inManagedObjectContext:managedObjectContext]; [fetchRequest setEntity:entity]; NSSortDescriptor *sort = [[NSSortDescriptor alloc] initWithKey:@"downloadCount" ascending:NO]; [fetchRequest setSortDescriptors:[NSArray arrayWithObject:sort]]; NSPredicate *predicate = [NSPredicate predicateWithFormat:@"showId IN %@", resultsArray]; [fetchRequest setPredicate:predicate]; [fetchRequest setFetchBatchSize:20]; NSFetchedResultsController *theFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:managedObjectContext sectionNameKeyPath:nil cacheName:nil]; self.fetchedResultsController = theFetchedResultsController; _fetchedResultsController.delegate = self; [sort release]; [fetchRequest release]; [theFetchedResultsController release]; return _fetchedResultsController; } </code></pre>
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