The Regular Expressions and GUID.

Question

Hello gurus, I hope you can help me!
I am needing to select GUIDS from a table and for this, I need the Regular Expression. My
Perl is not good and not good Regular Expression. My database is Oralce 11.2.0.2.0 and
the Operating System of the Machine is Linux (Oracle Version 6). If you require the further information,
I will watch closely. Thank you. Jehangir.

Answer 1

>
Hi Jehangir and welcome to the forums.
I am needing to select GUIDS from a table and for this,Well, the first thing you should do is read the forum FAQ and also the post by BluShadow
at the top of the posts on the forum home page. You should have provided code (DDL
and DML) showing your particular problem, but since this is your first time, I'll be gentle ;)
We have done this - sometimes clients have GUIDs as PKs and we need to send data to
their systems, but it isn't as simple as it may first appear.
GUIDs can come in three formats.
The Oracle one - SELECT Sys_GUID() from DUAL which is just a string of 32 Hexadecimal characters.
Then the string with hyphens and then the string with hypens and {} at beginning and end (see
sample data).
with datax as
  SELECT '79A864CCD8E44CD8B0A2765DF9EF337B' as guid  FROM DUAL  UNION ALL
  SELECT '79A864CFD8E44CD7B0A2765DF9EF337B' FROM DUAL UNION ALL
  SELECT '8gdfsgsgfdg' FROM DUAL UNION ALL  -- dummy for testing
  SELECT '21EC2020-3AEA-1069-A2DD-08002B30309D' FROM DUAL UNION ALL
  SELECT '21EC5550-3AEA-1069-A2FF-08002B30309D' FROM DUAL UNION All
  SELECT '{21CC2020-3AFA-1A69-A2DD-08002B30309D}' FROM DUAL
-- first one is the Oracle format
select * from datax where regexp_like(guid, '[0-9a-fA-F]{32}'); -- Oracle select sys_guid();
-- second one is with hyphens
select * from datax where regexp_like(guid, '[0-9a-fA-F]{8}\-[0-9a-fA-F]{4}\-[0-9a-fA-F]{4}\-[0-9a-fA-F]{4}\-[0-9a-fA-F]{12}');
-- third one is with hyphens and curly brackets.
select * from datax where regexp_like(guid, '^\{[0-9a-fA-F]{8}\-[0-9a-fA-F]{4}\-[0-9a-fA-F]{4}\-[0-9a-fA-F]{4}\-[0-9a-fA-F]{12}\}$');
-- This converts both of the last two formats back into Oracle format, which is what
-- we use. Notice, that I haven't used regualar expressions to do this. Regexes are
-- computationally expensive, and you should use Oracle's string furnctions if possible
SELECT REPLACE(REPLACE(REPLACE(GUID, '{', ''), '}', ''), '-', '')  FROM Datax;HTH,
Paul...
Jehangir.