如何通過nspredicate date過濾SQL結果？

Question

我想按日期過濾sql lite數據庫結果，但我很糟糕在ios日期和時間對象，並不確定如何做到這一點。您如何設置NSPredicate以在今天，過去7天，過去30天和過去90天過濾結果？

感謝

Answer 1

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; 
}