Coredata Conditionally Fetching on Nsdate Using Nspredicate (Swift)

CoreData conditionally fetching on NSDate using NSPredicate (swift)

I guess you are sending parameters to the predicate in NSDate format :

let predicate = NSPredicate(format: "time>= \(startTime) AND time<= \(endTime)")

Here your startTime and endTime is of type NSDate . Try to convert it in String format and pass it to the predicate . It should work .

Reference : NSPredicate: filtering objects by day of NSDate property

Unable to query for date using NSPredicate in Swift

NSPredicate(format:_:) takes a format string and a list of arguments, but you're passing a simple string. This doesn't work, since this initializer doesn't just call stringWithFormat: on the parameters, but actually looks at the arguments' type information as it's building the predicate.

You can use that initializer by passing the date as an argument:

let datePredicate = NSPredicate(format: "date > %@", currentDate)

How fetch objects with NSDate of today using NSPredicate?

What I do is compare it to the start and end of the day and have a couple helper functions to calculate them:

class DateHelper{
    internal class func startOfDay(day: NSDate) -> NSDate {
        let gregorian = NSCalendar(calendarIdentifier: NSCalendarIdentifierGregorian)
        let unitFlags: NSCalendarUnit = [.Minute, .Hour, .Day, .Month, .Year]
        let todayComponents = gregorian!.components(unitFlags, fromDate: day)
        todayComponents.hour = 0
        todayComponents.minute = 0
        return (gregorian?.dateFromComponents(todayComponents))!
    }

    internal class func endOfDay(day: NSDate) -> NSDate {
        let gregorian = NSCalendar(calendarIdentifier: NSCalendarIdentifierGregorian)
        let unitFlags: NSCalendarUnit = [.Minute, .Hour, .Day, .Month, .Year]
        let todayComponents = gregorian!.components(unitFlags, fromDate: day)
        todayComponents.hour = 23
        todayComponents.minute = 59
        return (gregorian?.dateFromComponents(todayComponents))!
    }
}

So in your code, you would call:

request.predicate = NSPredicate(format: "(dateStart => %@) AND (dateStart <= %@)", DateHelper.startOfDay(today), DateHelper.endOfDay(today))

Display results from CoreData using NSPredicate in Swift

The predicate needs to be added to the fetch request, for example:

let request = NSFetchRequest(entityName: "Your entity name")
let predicate = NSPredicate(format: "A == %d", 1)
request.predicate = predicate

fetchedResultsController = NSFetchedResultsController(
  fetchRequest: request, 
  managedObjectContext: managedObjectContext!, 
  sectionNameKeyPath: nil, 
  cacheName: nil)

What goes to the predicate depends on your goals. In a next step you will need to update the fetch request and reload the data as you change the selected item in the segmented control. In your IBAction that is called when the segmented control changes, get sender.selectedSegmentIndex and create the new predicate based on the index.
The code to refetch will look something like this:
Swift 2

        fetchedResultsController.fetchRequest.predicate = NSPredicate(format: "A = %d", some_int_goes_here)
        do {
            try fetchedResultsController.performFetch()
        }
        catch let error as NSError {
            NSLog("%@", error.localizedDescription)
        }
        catch {
            fatalError()
        }
        tableView.reloadData()

If you do Swift 1.2, omit the error handling, of course, something like this:

fetchedResultsController.fetchRequest.predicate = NSPredicate(format: "A = %d", some_int_goes_here)
fetchedResultsController.performFetch()
tableView.reloadData()

Check Core Data for an entry with Today's Date & perform function

You need to use a date range from start of day to end of day (midnight to midnight) in a compound predicate. Here is a solution based on a similar SO question

var calendar = Calendar.current
calendar.timeZone = NSTimeZone.local

let dateFrom = calendar.startOfDay(for: Date())
let dateTo = calendar.date(byAdding: .day, value: 1, to: dateFrom)

let fromPredicate = NSPredicate(format: "timestamp >= %@", dateFrom as NSDate)
let toPredicate = NSPredicate(format: "timestamp < %@", dateTo! as NSDate)
let waterPredicate = NSPredicate(format: "drinkWater = %@", "1")

let request = NSFetchRequest<NSFetchRequestResult>(entityName: "Drink")
request.predicate = NSCompoundPredicate(andPredicateWithSubpredicates: [waterPredicate, fromPredicate, toPredicate])

NSPredicate: filtering objects by day of NSDate property

Given a NSDate * startDate and endDate and a NSManagedObjectContext * moc:

NSPredicate *predicate = [NSPredicate predicateWithFormat:@"(date >= %@) AND (date <= %@)", startDate, endDate];
NSFetchRequest *request = [[[NSFetchRequest alloc] init] autorelease];
[request setEntity:[NSEntityDescription entityForName:@"EntityName" inManagedObjectContext:moc]];
[request setPredicate:predicate];

NSError *error = nil;
NSArray *results = [moc executeFetchRequest:request error:&error];

URI typed attributes in CoreData: how to query with NSPredicate

I'm answering to not let that question without an answer, but in my opinion, we three @nylki (the author), @Joakim Danielson and myself answered it together. I'll mark it as "Community Wiki" then.

URI in CoreData is a for URL objects. It's written as such in the documentation of NSAttributeDescription.AttributeType for the NSAttributeDescription.AttributeType.uri.

LIKE keyword in the predicate is for String comparison as stated by the Predicate Format String Syntax documentation, so we need to use = instead.

So the answer is:

NSPredicate(format: "imageUrl = %@", imageUrl as CVarArg)

Or

NSPredicate(format: "imageUrl = %@", argumentArray: [imageUrl])

if we don't want to use the as CVarArg.

A better way to avoid typo would be to use %K placeholder which is for %K is a var arg substitution for a key path.. Combined to #keyPath():

NSPredicate(format: "%K = %@", argumentArray: [#keyPath(YourEntityClass.imageUrl), imageUrl])

That way, if we wrote by error "imageUrI = %@" with an uppercase i instead of l that with might not see, we ensure the path.

Can I use an NSPredicate in Swift with a nil argument?

It looks as if it is (with the current Xcode 6 beta 3 release) generally difficult
to pass nil in a variable argument list.

This seems to work:

let predicate = NSPredicate(format: "parentFolder == %@", 0)
print(predicate)
// Output: parentFolder == nil

But the easiest solution would be to simply write the predicate as

NSPredicate(format: "parentFolder == nil")

How to retrieve CoreData that satisfies a condition swift 2

You need to add a NSPredicate to your fetchRequest.

https://developer.apple.com/library/mac/documentation/Cocoa/Reference/Foundation/Classes/NSPredicate_Class/

fetchRequest.predicate = NSPredicate(format: "flag == %@", "3")

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