topic Re: FUnction to calculate unique key in Application Development and Automation Discussions

FUnction to calculate unique key

Former Member — Fri, 12 Aug 2011 15:53:43 GMT

Hi All,

I have a situation where my source is 32 char length and destination InfoObject is only 20 char length. I want to derive a 20 char or less key from 32 char and store it in my InfoObject. The key should be unique to a char sequence.

I should also be able to derive the 32 char from 20 char key generated. Does ABAP have any standard functions which would derive a hash value which is unique and from which you can again derive the original value.

Please help.

Devang.

Re: FUnction to calculate unique key

matt — Fri, 12 Aug 2011 17:00:42 GMT

Unless there's a lot of redundancy in the source, I can't think that it's even mathematically possible. There are more combinations possible with 32 characters than with 20.

matt

Re: FUnction to calculate unique key

Former Member — Fri, 12 Aug 2011 18:16:23 GMT

HI Matt,

I am sure that we dont have so much data that it will pass combination of 20char. So I think we should be good mathematically.

Thanks,

Devang.

Re: FUnction to calculate unique key

Sandra_Rossi — Fri, 12 Aug 2011 19:29:32 GMT

Hi,

I don't think what you're looking for is feasible, so you should better use the usual workaround : define a database table to store the values, with a primary key field made of 20 numeric digits, and data is 32 characters, and a unique index on the 32C field. Each new 32C value is assigned the next 20N number (like with a number range), and if it is an existing 32C value, then it returns the corresponding 20N key.

Sandra

Re: FUnction to calculate unique key

Clemenss — Sat, 13 Aug 2011 14:20:12 GMT

Hi Deva,

if you can create the uinique key yourself, you can use FM GUID_CREATE: You will get a unique identifier in 16 bytes raw hex format, 22 character upper/lower case ASCII char format and in 32 character uppercase ASCII format..

They are mutually convertible by FM GUID_CONVERT.

So you can use GUID_CREATE to get the 32 char source key - you can convert it to a 16 byte hex value for your object.

I don't know if this works as you did not say what it is all about.

Regards

Clemens