cloudkit - CKQuery 哪里谓词有引用而不是字段？

Question

我需要创建一个CKQuery，其中谓词包含记录的引用，而不是记录的字段。

像这样

let query = CKQuery(recordType: "OUP", predicate: NSPredicate(format: "o = %@", "FF4FB4A9-271A-4AF4-B02C-722ABF25BF44")

如何设置o是CKReference，而不是字段!

我收到此错误:

字段“o”的查询谓词中的字段值类型不匹配

Answer 1

您可以使用 CKRecord 或 CKRecordID(带或不带 CKReference)来匹配关系。

CK记录:

let predicate = NSPredicate(format: "artist == %@", artist)

CKRecordID:

let predicate = NSPredicate(format: "artist == %@", artistID)

CKReference 与 CKRecord:

let recordToMatch = CKReference(record: artist, action: CKReferenceAction.None)
let predicate = NSPredicate(format: "artist == %@", recordToMatch)

带有 CKRecordID 的 CKReference:

let recordToMatch = CKReference(recordID: artistID, action: CKReferenceAction.None)
let predicate = NSPredicate(format: "artist == %@", recordToMatch)