核心数据使用in子句对实体关系进行NSPredicate fetch [英] Core Data NSPredicate fetch on entity relationship using in clause

问题描述

我想能够使用IN子句搜索实体的关系。
我有以下设置：

I would like to be able to search the relationship of an entity using an IN clause. I have the following setup:

我想通过昵称数组发现所有与这些昵称相关联的人。

I would like to send over an array of nicknames and find all Persons associated with those nicknames.

//array of names to find
let nameArray: [String] = ["Tom", "Tommy", "Thomas"] 

// find all Persons who have a nickname associated with that person           
let predicate = NSPredicate(format: "ANY Person.nickName in %@",nameArray)
var fetch = NSFetchRequest(entityName: "Person")
fetch.predicate = predicate
var fetchError : NSError? = nil

// executes fetch
let results = context?.executeFetchRequest(fetch, error: &fetchError)

但是当我运行代码时，我得到以下错误：

But when I run the code, I get the following error:

'NSInvalidArgumentException' '未实现的谓词谓词生成：（ANY Person.nickName IN {Tom，Tommy，Thomas}）'

这里做错了？如果我删除谓词搜索，它返回所有的结果确定，但一旦我添加这一行，一切都会中断。

What am I doing wrong here? If I remove the predicate search, it returns all the results ok, but as soon as I add this line in, everything breaks.

推荐答案

p>您应该在 NSPredicate 中使用关系名称。

尝试此操作：

You should use the relationship name in your NSPredicate.
Try this:

let predicate = NSPredicate(format: "ANY personToNick.nickName in %@", nameArray)

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