Question

i need some help for getting my statics work…
I use core data to store my values from user input and each “line” has a time value.

Now i need to calculate some of these values that are in specific time range, lets say the last 30 days.
But i don’t know how to do it, i’m a little new to working with date and time rangers.

Can somebody help me out?

kind regards,
Ingemar

Answer 1

You need to use a predicate to filter your data.

NSManagedObjectContext *context; // Assume this exists.
NSEntityDescription *entityDescription; // Assume this exists.
NSDate minDate, maxDate; // Assume these exist.

NSFetchRequest *request = [[NSFetchRequest alloc] init];
[request setEntity:entityDescription];

NSPredicate *setPredicate:predicate = [NSPredicate predicateWithFormat:@"date BETWEEN %@",
                                     [NSArray arrayWithObjects:minDate, maxDate, nil]];
[request setPredicate:predicate];

NSError *error;
NSArray *filteredResult = [context executeFetchRequest:request error:&error];
// Handle error.

[request release];