ios - firebase - 在多个位置原子删除

Question

有没有办法在 Firebase 中执行原子删除？

docs说

You can also delete by specifying nil as the value for another write operation such as setValue or updateChildValues...Simultaneous updates made this way are atomic: either all updates succeed or all updates fail.

但我无法让它工作。我下面的代码返回错误

Cannot store object of type _SwiftValue at . Can only store objects of type NSNumber, NSString, NSDictionary, and NSArray

我在这里遗漏了什么或者文档有误吗？

var topNodeRef = FIRDatabase.database().reference()
var childUpdates: [String:Any?] = [:]

childUpdates.updateValue(nil, forKey: "/owner")
childUpdates.updateValue(nil, forKey: "/pet")

topNodeRef.updateChildValues(childUpdates)

Answer 1

如果其他人遇到同样的问题，我设法通过使用 NSNull() 而不是 nil

来修复它

var topNodeRef = FIRDatabase.database().reference()
var childUpdates: [String:Any] = [:]

childUpdates["/owner"] = NSNull()
childUpdates["/pet"] = NSNull()

topNodeRef.updateChildValues(childUpdates)