Unable to query for date using NSPredicate in Swift

Question

I'm trying to make a fetch for dates later than a specific date. My predicate is as follows:

NSPredicate(format: "date > \(currentDate)") 

When I executed the fetch request I caught an exception:

'Unable to parse the format string "date > 2015-07-08 03:00:00 +0000"' 

I thought I could make a query like that. What am I doing wrong?

Answer 1

In swift 3 the predicate changed to:

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

Answer 2

With Swift 3, according to your needs, you may choose one of 5 the following patterns in order to solve your problem.

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#1. Using NSPredicate init(format:​arguments:​) initializer with NSDate instance

NSPredicate has an initializer called init(format:​arguments:​) that has the following declaration:

init(format predicateFormat: String, arguments argList: CVaListPointer) 

Creates and returns a new predicate by substituting the values in an argument list into a format string and parsing the result.

When used with NSDate, you can set an instance of NSPredicate by using init(format:​arguments:​) as indicated below:

let date = NSDate() let predicate = NSPredicate(format: "date > %@", date) 

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#2. Using NSPredicate init(format:argumentArray:) initializer with NSDate instance

NSPredicate has an initializer called init(format:argumentArray:) that has the following declaration:

init(format predicateFormat: String, argumentArray arguments: [Any]?) 

Creates and returns a new predicate by substituting the values in a given array into a format string and parsing the result.

When used with NSDate, you can set an instance of NSPredicate by using init(format:​argumentArray:​) as indicated below:

let date = NSDate() let predicate = NSPredicate(format: "date > %@", argumentArray: [date]) 

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#3. Using NSPredicate init(format:​arguments:​) initializer with Date instance casted to NSDate

When used with Date, you can set an instance of NSPredicate by casting your Date instance to NSDate as indicated below:

let date = Date() let predicate = NSPredicate(format: "date > %@", date as NSDate) 

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#4. Using NSPredicate init(format:​arguments:​) initializer with Date instance casted to CVarArg

When used with Date, you can set an instance of NSPredicate by casting your Date instance to CVarArg as indicated below:

let date = Date() let predicate = NSPredicate(format: "date > %@", date as CVarArg) 

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#5. Using NSPredicate init(format:argumentArray:) initializer with Date instance

When used with Date, you can set an instance of NSPredicate by using init(format:argumentArray:) as indicated below:

let date = Date() let predicate = NSPredicate(format: "date > %@", argumentArray: [date])