fetchEventDays

fetchEventDays.m

- (void)fetchEventDays
{
    NSExpression *startDateTimeExpression = [NSExpression expressionForKeyPath:@"startDateTime"];
    NSExpression *minStartDateTime = [NSExpression expressionForFunction:@"min:" arguments:[NSArray arrayWithObject:startDateTimeExpression]];
    NSExpression *maxStartDateTime = [NSExpression expressionForFunction:@"max:" arguments:[NSArray arrayWithObject:startDateTimeExpression]];
    
    NSExpressionDescription *minStartDateTimeExpression = [[NSExpressionDescription alloc] init];
    minStartDateTimeExpression.name = @"minEventStartTime";
    minStartDateTimeExpression.expression = minStartDateTime;
    minStartDateTimeExpression.expressionResultType = NSDateAttributeType;
    
    NSExpressionDescription *maxStartDateTimeExpression = [[NSExpressionDescription alloc] init];
    maxStartDateTimeExpression.name = @"maxEventStartTime";
    maxStartDateTimeExpression.expression = maxStartDateTime;
    maxStartDateTimeExpression.expressionResultType = NSDateAttributeType;
    
    NSManagedObjectContext *context = [RKObjectManager sharedManager].managedObjectStore.mainQueueManagedObjectContext;
    NSEntityDescription* entity = [NSEntityDescription entityForName:@"NIModelScheduleData" inManagedObjectContext:context];
    NSAttributeDescription* startDayDesc = [entity.attributesByName objectForKey:@"startDay"];

    NSFetchRequest* fetch = [[NSFetchRequest alloc] init];
    fetch.entity = entity;
    fetch.propertiesToFetch = [NSArray arrayWithObjects:startDayDesc, minStartDateTimeExpression, maxStartDateTimeExpression, nil];
    fetch.propertiesToGroupBy = [NSArray arrayWithObject:startDayDesc];
    fetch.resultType = NSDictionaryResultType;
    
    NSError *error = nil;
    NSArray *results = [context executeFetchRequest:fetch error:&error];
    
    NSLog(@"%@", results);
}