来自数组元素的 NSPredicate IN 查询

问题描述

为一个古怪的标题道歉.我有一个 Int 数组，我想定义一个 NSPredicate 来过滤掉 connectionType 等于数组中包含的值的项目.

Apologies for a quirky title. I have an array of Ints and I would like to define an NSPredicate that will filter out items with connectionType equals to a value contained in the array.

所以基本上是这样的:

fetchRequest.predicate = NSPredicate(format: "connectionType IN { all items in array }

我发现了一些我认为可以解决这个问题的 Objective C 示例，但我刚刚进入 iOS 开发并且只使用过 Swift，所以在这里提供一些帮助将不胜感激:)

I've found some Objective C examples that I think deals with this, but I just got into iOS development and have only worked with Swift, so some help here would be greatly appreciated :)

我尝试这样做:

 fetchRequest.predicate = NSPredicate(format: "connectionType IN \(myIntArray)"

然而，这会返回一个 NSInvalidArgumentException.我觉得我很接近.

However, this returns an NSInvalidArgumentException. I feel I'm close though.

NSInvalidArgumentException', reason: 'Unable to parse the format string "connectionType IN [28, 28]"

如果我执行以下操作:

fetchRequest.predicate = NSPredicate(format: "connectionType IN %@", myArray)

我收到了这个错误:

NSInvalidArgumentException', reason: 'unimplemented SQL generation for predicate : (connectionType IN {28, 28})'

推荐答案

你会构造一个这样的谓词:

You would construct a predicate like this:

NSPredicate(format:"connectionType IN %@", yourIntArray)

我希望这会有所帮助.

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