从解析本地数据存储中删除对象 unpinAll 不起作用答案

【问题标题】：Remove objects from parse local datastore unpinAll not working从解析本地数据存储中删除对象 unpinAll 不起作用
【发布时间】：2017-01-06 06:40:34
【问题描述】：

所以我正在将一堆数据写入解析本地数据存储，但想在我固定新表之前删除旧表。问题是它似乎没有被删除，我最终得到了同一张表的多个条目。

这是将数据写入本地数据存储的代码。

 class func buildHistoryPart(selectedPartId: String? = nil) {

        let query = PFQuery(className: "Part")
            query.includeKey("fromPack")

            query.findObjectsInBackground { (objects, error) in

            if error != nil {

                print(error!)

            } else if let parts = objects {

                for object in parts {

                    //if the objectID is equal to the id of the part received
                    if object.objectId == selectedPartId {

                        // if the fromPack column has data
                        if let fromPack = object.object(forKey: "fromPack") as? PFObject {

                            // create the class name from the pack name of the selected part
                            if let className = (fromPack.object(forKey: "packName") as? String) {

                                // creeate PFObject to rretrieved fields to
                                let historyClass = PFObject(className: className) as PFObject

                                    //add the objects to new class
                                    historyClass.add(object.objectId as Any, forKey: "partId")
                                    historyClass.add(object.object(forKey: "partName") as Any, forKey: "partName")
                                    historyClass.add(fromPack.object(forKey: "packName")!, forKey: "packName")
                                    historyClass.add(fromPack.objectId as Any, forKey: "packId")


                                        // unpin the old data
                                        PFObject.unpinAll(inBackground: [historyClass], withName: "pinnedHistory", block: { (success, error) in

                                            if success {

                                                // if successful pin the new data
                                                PFObject.pinAll(inBackground: [historyClass], withName: "pinnedHistory")
                                            }
                                        })
                            }
                        }

                    }
                }
            }
        }
    }

它不会取消固定，每次我运行该函数时，我都会在 LDS 中得到一堆表。

-------------------- 编辑 --------------------

由于我无法使用他们记录的“withName”属性使解析函数工作，我得到的解决方法是调用一个专门查询相关表的函数，如果它在那里删除它。它工作正常，但如果有人知道为什么我的原始代码不起作用，我很想知道。

用这个代替上面所有的取消固定：

class BuildHistory {

// unpinall doesnt seem to wok so force it and return result
class func removeOldTable(className: String, completeBlock: @escaping (Bool) -> Void) {

    let queryRem = PFQuery(className: className)
        queryRem.fromLocalDatastore()
        queryRem.findObjectsInBackground { (objects, error) in

            if objects != nil {

                PFObject.unpinAll(inBackground: objects)

                completeBlock(true)

            }
        }
}

【问题讨论】：

标签： swift parse-platform parse-server parse-ios-sdk

【解决方案1】：

class BuildHistory {

// unpinall doesnt seem to wok so force it and return result
class func removeOldTable(className: String, completeBlock: @escaping (Bool) -> Void) {
let queryRem = PFQuery(className: className)
    queryRem.fromLocalDatastore()
    queryRem.findObjectsInBackground { (objects, error) in

        if objects != nil {

            PFObject.unpinAll(inBackground: objects)

            completeBlock(true)

        }
    }
}

【讨论】：