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POUnexpected behavior of NSFetchRequest
 

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  1. POUnexpected behavior of NSFetchRequest
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    <p>I have created few entities in context for saving it in db using </p> <pre><code>AppCalendarEntity *appCalendar = [AppCalendarEntity getInstanceWithManagedDocument:manageDocument]; </code></pre> <p>After adding a few entities I execute flowing fetch request</p> <pre><code> NSFetchRequest *requestToSeeIfCalendarWithIdExist = [NSFetchRequest fetchRequestWithEntityName:@"AppCalendarEntity"]; NSArray *result = [managedDocument.managedObjectContext executeFetchRequest:requestToSeeIfCalendarWithIdExist error:&amp;InternalError] ; </code></pre> <p>It returns me the result including only the entities I have added in context using first command and NOT the entries already saved in database. I have made sure that at this stage the document state is UIDocumentStateNormal.</p> <p>When I add this line to already open document (UIDocumentStateNormal) it returns me the expected result, i.e. it fetch results from db as well as memory context which has not yet been saved to db.</p> <pre><code>[managedDocument openWithCompletionHandler:^(BOOL success) { NSFetchRequest *requestToSeeIfCalendarWithIdExist = [NSFetchRequest fetchRequestWithEntityName:@"AppCalendarEntity"]; NSArray *result = [managedDocument.managedObjectContext executeFetchRequest:requestToSeeIfCalendarWithIdExist error:&amp;InternalError] ; } </code></pre> <p>My question is 1- I expect that the result of query should be the same in both cases. Why it is not so in the above case. 2- To me if document state is UIDocumentStateNormal I should not be calling "openWithCompletionHandler" in context to open the document. In this particular scenario what difference it is making in NSFetchRequest which gives me the desired result after adding this.</p> <p>Please let me know if I'm getting wrong</p> <p>Here is the complete code</p> <p>This is the complete code of the function </p> <pre><code> + (void ) saveCalendarArrayInDbIfItAlreadyDoesNotExist : (NSArray*) appCalendarArray managedDocument: (UIManagedDocument*) managedDocument completionBlock : ( void(^) (NSArray* ObjectSavedSuccesfully, NSError *InternalError)) handler { // i dont know why i have to do it :( if i dont add openWithCompletionHandler my query doesnt fetch result from db rather just do query in-memory context and not db [managedDocument openWithCompletionHandler:^(BOOL success) { void (^completionHandler)(NSArray* , NSError* ); completionHandler = [handler copy ]; NSError *error = nil; NSMutableArray *array = [[NSMutableArray alloc] init]; for (id appCalendar in appCalendarArray) { if([appCalendar isKindOfClass:[AppCalendarEntity class]]) { AppCalendarEntity *appCalendarEntity = (AppCalendarEntity*) appCalendar; NSFetchRequest *requestToSeeIfCalendarWithIdExist = [NSFetchRequest fetchRequestWithEntityName:@"MyEntity"]; requestToSeeIfCalendarWithIdExist.predicate = [NSPredicate predicateWithFormat:@"identifier = %@", appCalendarEntity.identifier]; NSError *InternalError = nil; [requestToSeeIfCalendarWithIdExist setShouldRefreshRefetchedObjects:YES]; NSArray *result = [managedDocument.managedObjectContext executeFetchRequest:requestToSeeIfCalendarWithIdExist error:&amp;InternalError] ; // "result" is different when we encapsulate it in openWithCompletionHandler and when we don't…….MY PROBLEM if(result == nil) { // return error } // 1 object always return that depict the in memory(context) object we created but not saved. I expect it should be zero because no object has yet been saved to database.. else if(result.count &gt; 1) { [managedDocument.managedObjectContext deleteObject:appCalendar]; } else { [array addObject:appCalendarEntity]; } } else { // error handling } } if (error != nil) { completionHandler (nil, error); return; } // saving all the objects [ managedDocument updateChangeCount:UIDocumentChangeDone ]; } </code></pre>
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    1. USAmna Irshad Sipra
    1. USAmna Irshad Sipra
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    1. This table or related slice is empty.
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      1. POUnexpected behavior of NSFetchRequest
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      1. VTUpMod
    1. COAre you sure that's all you are doing... just inserting objects into a MOC, and fetching? I bet there is something else you are dong in between... like calling save on the MOC, perhaps?
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      1. POUnexpected behavior of NSFetchRequest
      1. USJody Hagins
    2. COYes absolutely, because i made only this change in the same function and the function start working.
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      1. POUnexpected behavior of NSFetchRequest
      1. USAmna Irshad Sipra
    3. COIs it expected behaviour ?
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      1. POUnexpected behavior of NSFetchRequest
      1. USAmna Irshad Sipra
 

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