带有 groupBy 的 nspredicate 不喜欢带有 nsdate 的谓词比较

Posted 2023-03-04

【中文标题】带有 groupBy 的 nspredicate 不喜欢带有 nsdate 的谓词比较

【英文标题】：nspredicate with groupBy don't like predicate with nsdate compare

【发布时间】：2013-02-11 22:17:22

【问题描述】：

这段代码：

    entity = [NSEntityDescription entityForName:@"PerDestinationsStat" inManagedObjectContext:self.managedObjectContext];
    [fetchRequest setEntity:entity];
    //NSFetchedPropertyDescription *rateCodeDesc = [entity.propertiesByName objectForKey:@"rateCode"];
    [fetchRequest setPropertiesToGroupBy:[NSArray arrayWithObjects:[entity.propertiesByName objectForKey:@"rateCode"],[entity.propertiesByName objectForKey:@"rateCountry"],[entity.propertiesByName objectForKey:@"rateSpecific"],[entity.propertiesByName objectForKey:@"ratePrice"],[entity.propertiesByName objectForKey:@"allCalls"],[entity.propertiesByName objectForKey:@"acd"],[entity.propertiesByName objectForKey:@"asr"],[entity.propertiesByName objectForKey:@"cost"],[entity.propertiesByName objectForKey:@"duration"],[entity.propertiesByName objectForKey:@"income"],[entity.propertiesByName objectForKey:@"succesefulCalls"],nil]];
    [fetchRequest setResultType:NSDictionaryResultType];
    [fetchRequest setPropertiesToFetch:[NSArray arrayWithObjects:@"rateCode",@"rateCountry",@"rateSpecific",@"ratePrice",@"allCalls",@"acd",@"asr",@"cost",@"duration",@"income",@"succesefulCalls",nil]];
    predicate = [NSPredicate predicateWithFormat:@"(perHourStat.dateFrom > %@) and (perHourStat.dateTo < %@) and (perHourStat.originator.company == %@)",from,to,selected];
    [fetchRequest setPredicate:predicate];
    fetchedObjects = [self.managedObjectContext executeFetchRequest:fetchRequest error:&error];

找不到对象，但如果我使用：

    predicate = [NSPredicate predicateWithFormat:@" (perHourStat.originator.company == %@)",selected];

找到对象：

> Printing description of fetchedObjects: <_PFArray 0x100664fb0>(
> <PerHourStat: 0x101233810> (entity: PerHourStat; id: 0x10122f310
> <x-coredata://BBDDF3D7-EA50-4290-B03A-05349E74467E/PerHourStat/p1> ;
> data: 
>     acd = "0.03688591122627258";
>     allCalls = 3;
>     asr = 1;
>     cost = "0.1327892804145813";
>     dateFrom = "2013-02-11 21:00:00 +0000";
>     dateTo = "2013-02-11 21:59:59 +0000";
>     duration = "6.639464020729065";
>     income = "0.1991839206218719";
>     originator = "0x101236000 <x-coredata://BBDDF3D7-EA50-4290-B03A-05349E74467E/Originator/p1>";
>     perDestinationsStat = "<relationship fault: 0x104d2b9b0 'perDestinationsStat'>";
>     succesefulCalls = 3;
>     terminator = nil; )

from/to 与找到的对象中的 dateFrom 匹配：

> description of from: 2013-02-11 22:00:00 +0000
> description of to: 2013-02-12 21:59:59 +0000

【问题讨论】：

看起来您的日期比较应该失败，这可以解释为什么没有找到对象。

【参考方案1】：

您正在比较同一日期21:00 > 22:00。这将清楚地匹配 0 条记录。