GUIDS case sensitive?

[J.Marsch]

I notice that when I generate various guids, they appear to have a mix of
upper and lowercase letters.

Is the uniqueness of a guid case-sensitive?

In other words, if I generate a guid, and then store it in a database that
is case insensitive (or if I convert the letters to upper), is it still
statistically unique?

[Mattias Sjögren]

Re: GUIDS case sensitive?

[color=blue]
>Is the uniqueness of a guid case-sensitive?[/color]

No. A guid is really just 128 bits of data. The string representation
is just one way of making it a little easier to read and work with.



Mattias

--
Mattias Sjögren [MVP] mattias @ mvps.org
http://www.msjogren.net/dotnet/ | http://www.dotnetinterop.com
Please reply only to the newsgroup.

[Daniel Pratt]

Re: GUIDS case sensitive?

The "letters" you refer to are actually hex digits A-F, so no, case
doesn't matter.

Regards,
Dan

"J.Marsch" <jeremy@ctcdeve loper.com> wrote in message
news:%23BnAr12u DHA.620@TK2MSFT NGP10.phx.gbl.. .[color=blue]
> I notice that when I generate various guids, they appear to have a mix of
> upper and lowercase letters.
>
> Is the uniqueness of a guid case-sensitive?
>
> In other words, if I generate a guid, and then store it in a database that
> is case insensitive (or if I convert the letters to upper), is it still
> statistically unique?
>
>[/color]

[David Browne]

Re: GUIDS case sensitive?


"J.Marsch" <jeremy@ctcdeve loper.com> wrote in message
news:%23BnAr12u DHA.620@TK2MSFT NGP10.phx.gbl.. .[color=blue]
> I notice that when I generate various guids, they appear to have a mix of
> upper and lowercase letters.
>
> Is the uniqueness of a guid case-sensitive?
>
> In other words, if I generate a guid, and then store it in a database that
> is case insensitive (or if I convert the letters to upper), is it still
> statistically unique?
>
>[/color]

A GUID is a 128 bit structure. The normal string representation uses 32 hex
digits to represent the 32 nibbles in the structure, and is not
case-sensative.

EG
B864A17D-E6E6-49C0-AD41-DC7BBFCAF0D8

Other representations are concevable, eg base64, and if you have fewer than
25 characters, it MUST be case-sensative.

But you should consider storuing the GUID in a binary field in the database,
intead of a text field.

David

[J.Marsch]

Re: GUIDS case sensitive? (thanks)

Thank you to all who replied. At one time, I had been 100% sure that the
guids were a hexadecimal representation, but then someone asked me why the
digits A-F are mixed case (VS.Net 2003 tools | generate GUID -- seems as
though it's always the 3rd segment in the string). I didn't have an answer,
so suddenly I had to question my understanding of the universe.

I'm still out to lunch on the universe thing, but at least I know that I was
right about the guids <g>

Thanks again.

"J.Marsch" <jeremy@ctcdeve loper.com> wrote in message
news:%23BnAr12u DHA.620@TK2MSFT NGP10.phx.gbl.. .[color=blue]
> I notice that when I generate various guids, they appear to have a mix of
> upper and lowercase letters.
>
> Is the uniqueness of a guid case-sensitive?
>
> In other words, if I generate a guid, and then store it in a database that
> is case insensitive (or if I convert the letters to upper), is it still
> statistically unique?
>
>[/color]