SQL 从 UniqueIdentifier 转换为 BigInt 并返回？
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Convert from UniqueIdentifier to BigInt and Back?
提问by Snowy
declare @uu uniqueidentifier = 'C50B0567-F8CC-4219-A1E1-91C97BD9AE1B'
select @uu
declare @zaza bigint = ( select convert(bigint, convert (varbinary(8), @uu, 1)) )
select @zaza
select CONVERT( uniqueidentifier , convert( varbinary(16) , @zaza , 1 ) )
I thought I had a fast way to convert Unique Identifier values to a Big Int, and back. But there is a problem in my second convert. Can anyone comment on the right way to fully convert a GUID to a number and back? I am only getting part of the GUID and not the whole thing when I try to convert it back from the numeric representation to its original GUID.
我以为我有一种快速的方法可以将唯一标识符值转换为 Big Int，然后再返回。但是我的第二次转换有问题。任何人都可以评论将 GUID 完全转换为数字并返回的正确方法吗？当我尝试将其从数字表示形式转换回其原始 GUID 时，我只得到了 GUID 的一部分，而不是全部。
I want to pass an integer (I think it would be classified as a "Large BigInt" in MSSQL?) to a remote system and just use characters 0-9, and still get the random uniqueness of NewId().
我想将一个整数（我认为它在 MSSQL 中被归类为“Large BigInt”？）传递给远程系统，并且只使用字符 0-9，并且仍然获得 NewId() 的随机唯一性。
回答by galets
There is no problem with your second convert. When I run your SQL statement in SQL management studio, I get:
你的第二次转换没有问题。当我在 SQL management studio 中运行你的 SQL 语句时，我得到：
------------------------------------
C50B0567-F8CC-4219-A1E1-91C97BD9AE1B
(1 row(s) affected)
--------------------
7423352504965404994
(1 row(s) affected)
------------------------------------
C50B0567-F8CC-4219-0000-000000000000
(1 row(s) affected)
Since you are converting 8 byte value to 16-byte guid, half of guid will be zeroes, which is exactly what you are seeing.
由于您将 8 字节值转换为 16 字节 guid，因此 guid 的一半将为零，这正是您所看到的。
