如何通过nspredicate日期过滤SQL结果？

Question

我正在尝试按日期过滤sql lite数据库结果，但我对ios日期和时间对象很糟糕，并且不确定如何做到这一点。您如何设置NSPredicate以过滤今天，过去7天，过去30天和过去90天？

由于

Answer 1

示例

- (NSPredicate *)predicateForDateWithinLast30Days
{

    NSDate *currentDate = [NSDate date];// get the current date


    // get the date 30 days prior to current date

    NSCalendar *calendar = [NSCalendar currentCalendar];
    NSDateComponents *dateComps = [[NSDateComponents alloc] init];
    [dateComps setDay:-30];
    NSDate *date30DaysAgo = [calendar
          dateByAddingComponents:dateComps
          toDate:currentDate options:0];

    // create the predicate
    NSPredicate *last30DaysPredicate = [NSPredicate
          predicateWithFormat:@"dateToCompare > %@", date30DaysAgo];

    return last30DaysPredicate;
}