Yesss....I do. I try to avoid the problems that sequential integer ID's potentially cause. But then again, I avoid data-bearing (surrogate) keys altogether when I can. :-)


>>I don't remeber where I found the below code, but thanks to the original author. I have a coupla questions on it, though.
>> 1. What is this Windows library based on (NIC, hd id, etc)?
>> 2. How do I know these are "really" unique across time & space?
>>
>>*Create a Universally Unique ID
>>*Adapted from the book Visual FoxPro 5
>>*Enterprise Development One of the most
>>*common problems faced with developers
>>*is a method of creating unique keys. This
>>*is where a UUID (Univerally Unique ID)
>>*comes in. UUID's are a IEEE standard
>>*method of generating Universally Unique
>>*values. What this means is the values
>>*returned are unique across time and
>>*space. The code below calls the Windows API
>>*and returns a UUID.
>>
>>
>>Function getUUID
>>
>>*-- The UUID Create function is in this library
>>DECLARE Integer UuidCreate IN C:\Windows\System\RPCRT4.DLL ;
>> String @ UUID && note that mixed case is important for UuidCreate
>>
>>*-- Create a buffer
>>lcUUID = Space(16)
>>
>>*-- generate the key
>>=UUIDCreate(@lcUUID)
>>
>>*-- Convert the binaries to hex values
>>lcPart1 = BinAsHex(Substr(lcUUID,1,4))
>>lcPart2 = BinAsHex(Substr(lcUUID,5,4))
>>lcPart3 = BinAsHex(Substr(lcUUID,8,4))
>>lcPart4 = BinAsHex(Substr(lcUUID,13,4))
>>
>>Local lcRetVal
>>lcRetVal = lcPart1 + lcPart2 + lcPart3 + lcPart4
>>Return Left(lcRetVal,8) + "-" + substr(lcRetVal,9,4) + "-" + substr(lcRetVal,13,4) + "-" + ;
>> substr(lcRetVal,17,4) + "-" + Right(lcRetVal,12)
>>
>>PROCEDURE binashex
>>Parameters lcBin
>>* translates a binary string into character string of hex
>>LOCAL lcChars, lnBin
>>
>>lcChars = ""
>>FOR lnDigit = 1 TO LEN(lcBin)
>> lnBin = ASC(SUBSTR(lcBin, lnDigit, 1))
>> lcChars = lcChars + Hex2Char(INT(lnBin/16)) + ;
>> Hex2Char(MOD(lnBin,16))
>>ENDFOR
>>
>>RETURN(lcChars)
>>
>>PROCEDURE hex2char
>>* takes a hex digit value and returns a character from 0-9 & A-F
>>LPARAMETERS lnHex
>>DO CASE
>> CASE BETWEEN(lnHex,0,9)
>> lnAsc = 48 + lnHex
>> CASE BETWEEN(lnHex,10,15)
>> lnAsc = 65 + lnHex - 10
>>ENDCASE
>>RETURN(CHR(lnAsc))
>
>
>Microsoft says the values will never be duplicated. UUID is another name for GUID. However, do you really want a 16 byte ID when a 4 byte Integer will work?