所以我正在将一堆数据写入解析本地数据存储，但想在固定新表之前删除旧表。问题是它似乎没有被删除，并且我最终得到同一个表的多个条目。
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”属性让解析函数工作，所以我的解决方法是调用一个专门查询相关表的函数，如果它存在则删除它。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。
调用它来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)
}
}
}
最佳答案
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)
}
}
}
关于swift - 从解析本地数据存储中删除对象 unpinAll 不起作用，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/41500323/