nspredicate

问题 I want to query sqllite table by specifying a range. So it's like give me all records whose id column between 3000 and 3010. I tried what Apple recommends, but it didn't work. Here is what I tried and failed. NSPredicate *betweenPredicate = [NSPredicate predicateWithFormat: @"attributeName BETWEEN %@", @[@1, @10]]; I have 2 strings called start and end. I updated Apple's example as following. NSPredicate *betweenPredicate = [NSPredicate predicateWithFormat: @"%@ BETWEEN %@", columnName, @

问题 I'm creating an NSPredicateEditor in code and trying to achieve what I had hoped would be a fairly simple task. Basically, I would like to display a compound NSPredicateEditorRowTemplate (giving the user the option to perform matches when "All/Any/None of the following are true") and a number of fairly basic subrows beneath it. To do this, I construct my NSPredicateEditor and bind its value in order to save changes as the user edits their predicate. The issue I'm experiencing is that, no

问题 If my Author NSManagedObject model has a authorID attribute (determined by the server), will an NSFetchRequest perform better if the NSPredicate filters by authorID rather than the complete Author object? Let's say I'm fetching all Book NSManagedObject s by a certain author . Which predicateFormat is better? [NSPredicate predicateWithFormat:@"author = %@", anAuthor] or [NSPredicate predicateWithFormat:@"author.authorID = %@", anAuthor.authorID] What's the best way to profile this? I have Core

问题 I'm trying to filter a response from Facebook's API, the JSON looks like this: { "Data": [ { "first_name" : "Joe", "last_name" : "bloggs", "uuid" : "123" }, { "first_name" : "johnny", "last_name" : "appleseed", "uuid" : "321" } ] } I load this into a NSDictionary, accessing it like [[friendDictionary objectForKey:@"data"] allObjects] I'm now trying to filter based on the first_name and last_name based on when someone inputs a name into a textfield. Here's what I have but its failing horribly:

问题 I have a DB with the following relationships: A <<-->> B A: Members table; B: Activities table A Member has many Activities, and each Activity has many Members. So, a many to many relationship. When the user selects an Activity from a tableView, a new tableView should be pushed with all the Members that has that Activity. In the NSPredicate of the "child" tableView, I do: request.entity = [NSEntityDescription entityForName:@"Members" inManagedObjectContext:context]; request.predicate =

问题 Refactored to vanilla UIViewController Rather than having the UITableView toggle between active and inactive UISearchController , I refactored to a vanilla UIViewController with a UISearchBar at the top and a UITableView directly underneath it. What I'm trying to do is toggle the fetchedResultsController between having a predicate which is set by the text in the searchBar and one that grabs everything. I found this answer, which describes a solution to a similar problem in Objective-C and

问题 I tried to build a predicate in a previous post, but ended up doing it this way because after 3 hours, I couldn't get it to work. I feel like there has to be a more effective way, also I need the predicates to be case insensitive. 10,000 cars I have a tire, wheel, seat as three car parts I want to find all cars that have a tire. THEN I want to find all cars that have a wheel. THEN I want to find all cars that have a seat. (I know many will be duplicates, but that's what I need) Please let me

问题 I have a Song Entity and a Playlist Entity. Playlist can have multiple Songs and Songs can be linked to multiple Playlist. I have a ListToSongs Entity which maintains the order in which Songs were added to the Playlist. I am not using "Ordered Relationship" in ios5 (I am aware of its existence and I need more control over my model) and I store the order by a "sortOrder" field in PlayListToSong entity. So the schema is modeled as (relationship names are written in parentheses below): Song

问题 I'm attempting to use an IN clause with an NSPredicate. I'm getting the following error: *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[NSTaggedPointerString countByEnumeratingWithState:objects:count:]: unrecognized selector sent to instance 0xa000000000000611' Here's the code: let fetchRequest: NSFetchRequest<Employee> = NSFetchRequest(entityName: "Employee") fetchRequest.sortDescriptors = [ NSSortDescriptor.init(key: "lastName", ascending: true) ]

问题 Is there a particular way to configure an NSPredicate to compare dates? Essentially I have a Photo object that has an NSDate, lastViewed. I'd like to configure an NSPredicate that will return all the Photo objects that have been viewed more recently than a specified time period - typically two days. I'm obtaining the past date like so: NSTimeInterval secondsPast = -172800; NSDate * twoDaysPast = [NSDate dateWithTimeInterval:secondsPast sinceDate:[NSDate date]]; And configuring the NSPredicate