CORE DATA objectId不断更改 [英] CORE DATA objectId changes constantly
问题描述
我有一些数据，我导出到一个XML文件，并放在一个远程FTP服务器。
I have some data that I export into an XML file and put in a remote FTP Server.
我必须识别每个对象的唯一属性，
I have to identified each object with a unique attribute, it doesn't matter wich is, but must be persistent always => it can never change.
我不想创建一个唯一的属性，序列，序列等等。
I don't want to create a unique attribute, sequence, serial, etc.
我使用的是objectID，但每次使用它都会得到一个新的引用。
I'm using the objectID but every time I use it a get a new reference.
在对象被保存之前，它有一个'temporal id'，但一旦保存，它就会得到确定的。
I know that before the object has been saved, it has a 'temporal id', but once it's saved, it gets the definitive.
我没有看到这个，从来没有。
I'm not seeing this, never.
当我导出时，只是获取所有数据并循环，总是我得到一个新的引用：
When I export, just fetch all data and loop, and always I get a new reference:
NSURL *objectID = [[personalDataObject objectID] URIRepresentation];
// some of id received for the SAME OBJECT (no changes made, saved, ...)
// 61993296
// 62194624
感谢，
r。
我使用％d而不是％@，现在返回的数据是：
I was using %d instead of %@, now the returned data is:
x-coredata://F46F3300-8FED-4876-B0BF-E4D2A9D80913/DataEntered/p1
x-coredata://F46F3300-8FED-4876-B0BF-E4D2A9D80913/DataEntered/p2
推荐答案
。你显示的数字应该是一个URI / UUID是方法，简称。
I think this maybe a reporting problem. The numbers you show that are supposed to be a URI/UUID are way, way to short.
UUID（通用唯一的
标识符），也称为GUIDs
（全局唯一标识符）或IIDs
（接口标识符）是128位的
值，保证是唯一的。 UUID
在空间和
时间是唯一的，通过组合
所特有的值生成
的计算机 - 通常是以太网
硬件地址 - 和值
表示
的数量自从十月以来的100纳秒间隔
15,1582在00:00:00。
UUIDs (Universally Unique Identifiers), also known as GUIDs (Globally Unique Identifiers) or IIDs (Interface Identifiers), are 128-bit values guaranteed to be unique. A UUID is made unique over both space and time by combining a value unique to the computer on which it was generated—usually the Ethernet hardware address—and a value representing the number of 100-nanosecond intervals since October 15, 1582 at 00:00:00.
用ASCII表示的UUID
的标准格式是用连字符分隔的字符串
，例如
68753A44-4D6F-1226-9C60-0050E4C00067。
十六进制表示看起来像
可能期望的，像一个数字
值的列表前面的0x。例如，
0xD7，0x36，0x95，0x0A，0x4D，0x6E，
0x12,0x26,0x80,0x3A，0x00,0x50，
0xE4,0xC0,0x00,0x67。要使用
UUID，只需创建它，然后
将结果字符串复制到
头文件和C语言源文件中。
因为UUID简单地表示为
一个字节数组，所以对于
不同的平台没有
的字节顺序考虑。
The standard format for UUIDs represented in ASCII is a string punctuated by hyphens, for example 68753A44-4D6F-1226-9C60-0050E4C00067. The hex representation looks, as you might expect, like a list of numerical values preceded by 0x. For example, 0xD7, 0x36, 0x95, 0x0A, 0x4D, 0x6E, 0x12, 0x26, 0x80, 0x3A, 0x00, 0x50, 0xE4, 0xC0, 0x00, 0x67 . To use a UUID, you simply create it and then copy the resulting strings into your header and C language source files. Because a UUID is expressed simply as an array of bytes, there are no endianness considerations for different platforms.
我认为你看到的是不同的值，因为你每次检查UUID时只得到一个片段，并且有一个不同的片段。表示为URI，它们应该看起来更像一个URL。它们绝对不会像一个整数。
I think you're seeing different values because your only getting a piece, and a different piece at that, each time you check the UUID. Represented as a URI, they should look more like a URL. They definitely won't look like an integer.
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