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Asked: 2026-05-29T05:39:52+00:00

Now, I need to use a predicate for a NSFetchRequest. But things here are

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Now, I need to use a predicate for a NSFetchRequest.

But things here are a little different, since there are two nested to-many relationships for the predicate to go through.

For instance, my entities are like this:

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Now I need to fetch some Month and Week ManagedObjects, but the requirement is that the amount of Events of a Day of the needed Weeks or Months is more than one.

In another word, with reference to a given Week or Month, if any Day on the destination of its “days” relationship has at least one Event, then take it.

So that is a nested to-many relationship, and I don’t know how to set the predicate string.

There are two troubles:

  1. I know ALL and ANY keyword. But could @"ANY days.ANY events" be the keypath? Or how is it supposed to be?

  2. How to judge that the events relationship points to at least one Event object.

Would [@"%K != nil",theCorrectKeypath] work? I’m afraid of that “!= nil” does not equal to at least one destination object?

Waiting for someone to help me out.

Terribly thanks!

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1 Answer

  1. Editorial Team

    I found the answer my self.

    There’s another way to get this, because of my condition, I can just predicate the suitable Events objects, and all the way from Events to Week or Month are to-one relationship,

    so once I got the eligible Events,

    I can just get corresponding Weeks and Months by

    theEvent.date.thisWeek or theEvent.date.thisMonth.

    Thanks for your guys,

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