NSPredicate时间间隔 [英] NSPredicate for time interval

问题描述

我有一个表有4个字段startdate，enddate，starttime和endtime。我需要设置谓词

I have one table with 4 fields startdate ,enddate, starttime and endtime. I need to set predicate something like

if
   startdate<= currentdate and currentdate <= enddate
   if 
      starttime <= currenttime and endtime <= endtime
   else
      starttime <= currenttime and currenttime<= 23.00 or 0.00 <= currentime and currentime <= endtime   

如何为这种类型的条件设置谓词。当前日期和当前时间是我的系统时间（以gmt为单位）。

How i set predicate for this type of condition.Current date and current time is the my system time in gmt.

推荐答案

您可以使用 NSCompoundPredicate

创建 NSMutableArray 使用条件保存您的谓词

Create NSMutableArray to hold your predicates with their conditions

NSMutableArray *conditions = [NSMutableArray array];

创建条件并将它们添加到此数组

Build your conditions and add them to this array

[conditions addObject:[NSPredicate predicateWithFormat:@"startdate <= %@ AND enddate <= %@",[NSDate date],[NSDate date]]];

添加任意多个条件。最后建立您的 NSCompoundPredicate

Add as many conditions as you like. Finally build your NSCompoundPredicate

NSPredicate *predicate = [NSCompoundPredicate andPredicateWithSubpredicates:conditions];

如果您有 startdate c $ c> enddate in NSDate 格式，你也可以访问它的时间组件，没有必要单独的 starttime 和 endtime 只是比较两个日期，应该可以。

If you have your startdate and enddate in NSDate format you can access it time component as well, there is no need of separate starttime and endtime just compare the two dates and should be ok.

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