search by date in coredata

How to predict all the data that inserted the last week , the开发者_运维问答 last month yesterday

I have nsdate field in my coredata but I don't know how to search using it

I suppose you have a fetchedResultsController set up for retrieving objects from the database. You have to add an NSPredicate to your fetchRequest when you set up the fetchedResultsController.

Dates shamelessly stolen from here

//You can set up your custom dates like this
NSDate *today = [NSDate date];

NSDate *yesterday = [today addTimeInterval: -86400.0];
NSDate *thisWeek  = [today addTimeInterval: -604800.0];
NSDate *lastWeek  = [today addTimeInterval: -1209600.0];

// This predicate retrieves all the object created since last week.
NSpredicate *predicate = [NSPredicate predicateWithFormat:@"yourDateField >= %@ ", lastWeek];
[fetchRequest setPredicate:predicate];    

// You can add sorting like this
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"yourDateField" ascending:YES];
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil];

[fetchRequest setSortDescriptors:sortDescriptors];