保存和获取CloudKit参考

Question

I'm having trouble creating with CloudKit References. Data is being saved into CloudKit but its not referencing its parent (list). Don't know what i'm doing wrong, any help would be much appreciated!

Saving Method

var list: CKRecord?
var item: CKRecord?    

@objc func save() {
    let name = nameTextField.text! as NSString

    //Fetch Private Database
    let privateDatabase = CKContainer.default().privateCloudDatabase

    if item == nil {
        //Create Record
        item = CKRecord(recordType: RecordTypeItems)

        //Initialization Reference
        guard let recordID = list?.recordID else { return }
        let listReference = CKRecord.Reference(recordID: recordID, action: .deleteSelf)

        item?.setObject(listReference, forKey: "list")
    }

    item?.setObject(name, forKey: "name")

    //Save Record
    privateDatabase.save(item!) { (record, error) in
        DispatchQueue.main.sync {
            self.processResponse(record: record, error: error)
        }
    }
}

Fetch Method

var list: CKRecord!
var items = [CKRecord]()

private func fetchItems() {
    //Fetch Private Database
    let privateDatabase = CKContainer.default().privateCloudDatabase

    //Initialize Query
    guard let recordID = list?.recordID else { return }
    let reference = CKRecord.Reference(recordID: recordID, action: .deleteSelf)
    let query = CKQuery(recordType: RecordTypeItems, predicate: NSPredicate(format: "list == %@", [reference]))


    //Configure Query
    query.sortDescriptors = [NSSortDescriptor(key: "name", ascending: true)]

    //Peform Query
    privateDatabase.perform(query, inZoneWith: nil) { (records, error) in
        DispatchQueue.main.sync {
            self.processResponseForQuery(records: records, error: error)
        }
    }
}

Answer 1

Where you are creating your query to retrieve items referencing the list, should the list reference in the predicate format string be inside an array? If you create the item's reference like item?.setObject(listReference, forKey: "list") , CloudKit will infer the list field to be a single CKRecord.Reference , so the query would be:

let query = CKQuery(recordType: RecordTypeItems, predicate: NSPredicate(format: "list == %@", reference))