select sum(amount), date from db.table group by date;

// Retrieve the entity from the local store -- much like a table in a database
    NSEntityDescription *entity = [NSEntityDescription entityForName:@"AppSettings" inManagedObjectContext:managedObjectContext];
    NSFetchRequest *request = [[NSFetchRequest alloc] init];
    [request setEntity:entity];


// Set the predicate -- much like a WHERE statement in a SQL database
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"version == %@", @"Default"];
[request setPredicate:predicate];


// Set the sorting -- mandatory, even if you're fetching a single record/object

NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"version" ascending:YES];
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil];
[request setSortDescriptors:sortDescriptors];
sortDescriptors = nil;
sortDescriptor = nil;

// Request the data -- NOTE, this assumes only one match, that
// yourIdentifyingQualifier is unique. It just grabs the first object in the array.
AppSettings *appSettings1 =[[managedObjectContext executeFetchRequest:request error:&error] objectAtIndex:0];

request = nil;


//Update the object
appSettings1.backGroundImage = [NSNumber numberWithInt: backGroundGraphics.selectedSegmentIndex];