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PONSFetchedResultsController sections name - Tracking EFFICIENCY
 

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    <p>This is my core data structure</p> <p>Entity - <strong>Category</strong></p> <p>Attr - <strong>Id</strong>(NSString) <strong><em>primary key</em></strong>, <strong>name</strong>(NSString)</p> <p>Entity - <strong>Product</strong></p> <p>Attr - <strong>Id</strong>(NSString), <strong>name</strong>(NSString), <strong>parentCategoryId</strong>(NSString) <strong><em>foreign key</em></strong>,....</p> <p>As can be seen from above, <em>Id from Category</em> points to <em>parentCategoryId from Product</em>.</p> <p>In this case, I want to use <em>name from category</em> associated with concerned <em>parentCatrgoryId from product</em> as my section name for UITableView.(I use @"parentCategoryId" as key to NSSortDescriptors in fetchrequest) But <em>parentCatrgoryId</em> are simply alphanumeric texts.</p> <p>How can I decode the the alphanumeric text i.e. <em>parentCatrgoryId from product</em> to <em>name from category</em></p> <p><strong>EDIT</strong></p> <p><em><strong>This is what I did &amp; its working. But what I want to ask if what I did is efficient.</em></strong></p> <p>I added one more attribute named <strong>parentCategoryIdName</strong> &amp; used this to store the exact name by computing some simple operation.</p> <p>.h file</p> <pre><code>@property (nonatomic, retain) NSMutableArray *categoryArr; @property (nonatomic, retain) NSMutableArray *productArr; </code></pre> <p>.m file</p> <pre><code> NSEntityDescription *entity = [NSEntityDescription entityForName:@"Category" inManagedObjectContext:self.MOContext]; // Setup the fetch request NSFetchRequest *request = [[NSFetchRequest alloc] init]; [request setEntity:entity]; // [request setPredicate:[NSCompoundPredicate andPredicateWithSubpredicates:subpredicates]]; NSError *error; NSMutableArray *mutableFetchResults = [[self.MOContext executeFetchRequest:request error:&amp;error] mutableCopy]; [self setCategoryArr: mutableFetchResults]; NSEntityDescription *entity2 = [NSEntityDescription entityForName:@"Product" inManagedObjectContext:self.MOContext]; // Setup the fetch request NSFetchRequest *request2 = [[NSFetchRequest alloc] init]; [request2 setEntity:entity2]; // [request2 setPredicate:[NSPredicate predicateWithFormat:@""]]; NSError *error2; NSMutableArray *mutableFetchResults2 = [[self.MOContext executeFetchRequest:request2 error:&amp;error2] mutableCopy]; [self setProductArr: mutableFetchResults2]; </code></pre> <p>To insert the data in DB</p> <pre><code> for (int i=0; i&lt; [self.productArr count]; i++) { Product *productEnt = [self.productArr objectAtIndex:i]; NSManagedObjectContext *context = self.MOContext; for (int j=0; j&lt;self.categoryArr.count; j++) { Category *categroy = [self.categoryArr objectAtIndex:j]; if ([categroy.objectId isEqualToString:productEnt.parentCategoryId]) { [productEnt setParentCategoryIdName:categroy.name]; } // Save the context. NSError *error = nil; if (![context save:&amp;error]) { // Replace this implementation with code to handle the error appropriately. // abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development. NSLog(@"Unresolved error %@, %@", error, [error userInfo]); abort(); } } </code></pre>
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    1. UShp iOS Coder
    1. UShp iOS Coder
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    1. COCan you plz post your fetch request code.
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      1. PONSFetchedResultsController sections name - Tracking EFFICIENCY
      1. USAbid Hussain
    2. COYou may see here http://stackoverflow.com/questions/5011363/section-names-from-nsfetchedresultscontroller-dont-match-the-managed-object-val
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      1. PONSFetchedResultsController sections name - Tracking EFFICIENCY
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    3. COsee my edited question. It includes the answer but I want to know what I did is efficient or not?
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      1. UShp iOS Coder
 

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