NSPredicate：通过NSDate的财产的一天过滤对象

Question

我有一个NSDate性的核心数据模型。我想过滤白天数据库。我认为解决方案将涉及的NSPredicate，但我不知道如何把它一起。

我知道如何使用NSDate和NSDateComponents 2个NSCalendars的日子比较，但我怎么用NSPredicate过滤呢？

也许我需要创建我的NSManagedObject子类别，可以只用年，月，日返回裸日期。然后，我可以比较的是，在NSPredicate。这是您的建议，或者是有什么简单？

Answer 1

给定一个的NSDate * 的startDate 和结束日期和的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];

Answer 2

实施例，关于如何还设置了的startDate和结束日期以上面给出的答案：

...

NSCalendar *calendar = [NSCalendar currentCalendar];
NSDateComponents *components = [calendar components:(NSCalendarUnitYear | NSCalendarUnitMonth ) fromDate:[NSDate date]];
//create a date with these components
NSDate *startDate = [calendar dateFromComponents:components];
[components setMonth:1];
[components setDay:0]; //reset the other components
[components setYear:0]; //reset the other components
NSDate *endDate = [calendar dateByAddingComponents:components toDate:startDate options:0];
predicate = [NSPredicate predicateWithFormat:@"((date >= %@) AND (date < %@)) || (date = nil)",startDate,endDate];

...

在这里，我一个月内搜索所有条目。值得一提，这个例子也说明了如何搜索“零”日期entires。

Answer 3

在斯威夫特我有类似的东西：

        let dateFormatter = NSDateFormatter()
        dateFormatter.dateFormat = "yyyy-MM-dd"
        let date = dateFormatter.dateFromString(predicate)
        let calendar = NSCalendar(calendarIdentifier: NSGregorianCalendar)
        let components = calendar!.components(
            NSCalendarUnit.CalendarUnitYear |
                NSCalendarUnit.CalendarUnitMonth |
                NSCalendarUnit.CalendarUnitDay |
                NSCalendarUnit.CalendarUnitHour |
                NSCalendarUnit.CalendarUnitMinute |
                NSCalendarUnit.CalendarUnitSecond, fromDate: date!)
        components.hour = 00
        components.minute = 00
        components.second = 00
        let startDate = calendar!.dateFromComponents(components)
        components.hour = 23
        components.minute = 59
        components.second = 59
        let endDate = calendar!.dateFromComponents(components)
        predicate = NSPredicate(format: "day >= %@ AND day =< %@", argumentArray: [startDate!, endDate!])

我有一个很难发现，串插"\(this notation)"不会在NSPredicate比较日期的工作。

Answer 4

我移植从 Glauco内韦斯中的答案夫特2.0和包裹它接收的日期，并返回该函数内部NSPredicate用于相应天：

func predicateForDayFromDate(date: NSDate) -> NSPredicate {
    let calendar = NSCalendar(calendarIdentifier: NSCalendarIdentifierGregorian)
    let components = calendar!.components([.Year, .Month, .Day, .Hour, .Minute, .Second], fromDate: date)
    components.hour = 00
    components.minute = 00
    components.second = 00
    let startDate = calendar!.dateFromComponents(components)
    components.hour = 23
    components.minute = 59
    components.second = 59
    let endDate = calendar!.dateFromComponents(components)

    return NSPredicate(format: "day >= %@ AND day =< %@", argumentArray: [startDate!, endDate!])
}

Answer 5

3.0斯威夫特延长日期：

extension Date{

func makeDayPredicate() -> NSPredicate {
    let calendar = Calendar.current
    var components = calendar.dateComponents([.year, .month, .day, .hour, .minute, .second], from: self)
    components.hour = 00
    components.minute = 00
    components.second = 00
    let startDate = calendar.date(from: components)
    components.hour = 23
    components.minute = 59
    components.second = 59
    let endDate = calendar.date(from: components)
    return NSPredicate(format: "day >= %@ AND day =< %@", argumentArray: [startDate!, endDate!])
}
}

然后，使用这样的：

 let fetchReq = NSFetchRequest(entityName: "MyObject")
 fetchReq.predicate = myDate.makeDayPredicate()

Answer 6

添加到拉斐尔的回答（非常有用的，谢谢！），移植了斯威夫特3。

func predicateForDayFromDate(date: Date) -> NSPredicate {
    let calendar = Calendar(identifier: Calendar.Identifier.gregorian)
    var components = calendar.dateComponents([.year, .month, .day, .hour, .minute, .second], from: date)
    components.hour = 00
    components.minute = 00
    components.second = 00
    let startDate = calendar.date(from: components)
    components.hour = 23
    components.minute = 59
    components.second = 59
    let endDate = calendar.date(from: components)

    return NSPredicate(format: "YOUR_DATE_FIELD >= %@ AND YOUR_DATE_FIELD =< %@", argumentArray: [startDate!, endDate!])
}

Answer 7

最近，我花了一些时间来尝试解决这个同样的问题，下面添加到替代品的清单准备开始和结束日期（包括更新的方法适用于iOS 8.0及以上）...

NSDate *dateDay = nil;
NSDate *dateDayStart = nil;
NSDate *dateDayNext = nil;

dateDay = <<USER_INPUT>>;

dateDayStart = [[NSCalendar currentCalendar] startOfDayForDate:dateDay];

//  dateDayNext EITHER
dateDayNext = [dateDayStart dateByAddingTimeInterval:(24 * 60 * 60)];

//  dateDayNext OR
NSDateComponents *dateComponentDay = nil;
dateComponentDay = [[NSDateComponents alloc] init];
[dateComponentDay setDay:1];
dateDayNext = [[NSCalendar currentCalendar] dateByAddingComponents:dateComponentDay
                                                            toDate:dateDayStart
                                                           options:NSCalendarMatchNextTime];

...和用于核心数据NSPredicate的NSFetchRequest（如已经示出上述在其他的答案）...

[NSPredicate predicateWithFormat:@"(dateAttribute >= %@) AND (dateAttribute < %@)", dateDayStart, dateDayNext]]

Answer 8

有关我这是工作。

NSCalendar *calendar = [NSCalendar currentCalendar];
    NSDateComponents *components = [calendar components:(NSYearCalendarUnit | NSMonthCalendarUnit ) fromDate:[NSDate date]];
    //create a date with these components
    NSDate *startDate = [calendar dateFromComponents:components];
    [components setMonth:0];
    [components setDay:0]; //reset the other components
    [components setYear:0]; //reset the other components
    NSDate *endDate = [calendar dateByAddingComponents:components toDate:startDate options:0];

    startDate = [NSDate date];
    endDate = [startDate dateByAddingTimeInterval:-(7 * 24 * 60 * 60)];//change here

    NSString *startTimeStamp = [[NSNumber numberWithInt:floor([endDate timeIntervalSince1970])] stringValue];
    NSString *endTimeStamp = [[NSNumber numberWithInt:floor([startDate timeIntervalSince1970])] stringValue];


   NSPredicate *predicate = [NSPredicate predicateWithFormat:@"((paidDate1 >= %@) AND (paidDate1 < %@))",startTimeStamp,endTimeStamp];
    NSLog(@"predicate is %@",predicate);
    totalArr = [completeArray filteredArrayUsingPredicate:predicate];
    [self filterAndPopulateDataBasedonIndex];
    [self.tableviewObj reloadData];
    NSLog(@"result is %@",totalArr);

我已过滤从当前日期阵列至7天回来。我的意思是我从当前的日期越来越1周数据。这应该工作。

注意：我转换其由1000用milli秒到来日期，和之后比较。让我知道如果你需要任何清晰。