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POsaving only one attribute value out of two for an entity
 

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  1. POsaving only one attribute value out of two for an entity
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    <p>I have an entity named <code>Attribute</code>, it has 2 attributes <code>attribute_name</code> and <code>attribute_value</code>.</p> <p>This <code>Attribute</code> <code>entity</code> is in on-to-many relationship with another entity named <code>Project</code>. I want to insert it like all the <code>attribute_name</code> for the one project to be same and only <code>attribute_value</code> to be different. </p> <p>When I enter data, I take these attributes for <code>Attribute</code> entity in two different arrays and save them in go on clicking <code>Save</code> button using a <code>for</code> loop.</p> <p>In order to keep <code>attribute_name</code> distinct, I check if they already exist in the data base,if yes then I only save <code>attribute_value</code>. But it still inserts "attributes_name" as <code>NULL</code>. Data is getting saved for <code>attributes_name</code>.</p> <p>So,when i click "save" button second time,I get double the textfield than before.which are empty.</p> <pre><code>NSFetchRequest * request = [[NSFetchRequest alloc] init]; [request setEntity:[NSEntityDescription entityForName:@"Attributes" inManagedObjectContext:self.context]]; [request setPredicate:[NSPredicate predicateWithFormat:@"attribute_name in %@", applicationDelegate.attributesTextArray]]; NSError * error; NSArray * anArray = [context executeFetchRequest:request error:&amp;error]; for (int i = 0; i &lt; [applicationDelegate.attributesTextArray count]; i++) { attributesObject = (Attributes*)[NSEntityDescription insertNewObjectForEntityForName:@"Attributes" inManagedObjectContext:self.context]; if (anArray.count == 0) { attributesObject.attribute_name = [applicationDelegate.attributesTextArray objectAtIndex:i]; attributesObject.attribute_value = [applicationDelegate.attributeGradesArray objectAtIndex:i]; } else { attributesObject.attribute_value = [applicationDelegate.attributeGradesArray objectAtIndex:i]; } [testArray addObject:attributesObject]; } for (int o=0; o&lt;[testArray count]; o++) { NSData * retrievedData = [[NSUserDefaults standardUserDefaults] objectForKey:@"ProjectManagedObject"]; NSURL * retrievedUrl = [NSKeyedUnarchiver unarchiveObjectWithData:retrievedData]; NSManagedObjectID * projectObjectId = [applicationDelegate.persistentStoreCoordinator managedObjectIDForURIRepresentation:retrievedUrl]; projectObject = (Project*)[applicationDelegate.managedObjectContext objectWithID:projectObjectId]; [projectObject addAttributesObject:[testArray objectAtIndex:o]]; NSError * error; if (![context save:&amp;error]) { NSLog(@"UNABLE TO SAVE DATA: %@", [error userInfo]); } </code></pre> <p>What exactly is going wrong here ? </p> <p>UPDATE: </p> <pre><code>NSFetchRequest * fetchRequest = [[NSFetchRequest alloc] init]; NSEntityDescription * entity = [NSEntityDescription entityForName:@"Project" inManagedObjectContext:context]; [fetchRequest setEntity:entity]; NSError * error; NSArray * fetchedObjects = [context executeFetchRequest:fetchRequest error:&amp;error]; NSLog(@"OBJECT FETCHED:%d", [fetchedObjects count]); if (fetchedObjects.count != 0) { Project * project_ = [fetchedObjects objectAtIndex:applicationDelegate.projectNumber]; NSArray * saved_attributes = [project_.attributes allObjects]; if (saved_attributes.count != 0) { //Update "attribute-value" } else { // create new attribute and insert both "attribute_name" and "attribute_value" ? } </code></pre>
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    1. This table or related slice is empty.
 

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