Matching a group that may or may not exist

Question

My regex needs to parse an address which looks like this:

BLOOKKOKATU 20 A 773 00810 HELSINKI SUOMI
-------------------- ----- -------- -----
          1                 


        

Answer 1

(.*?)\s(\d{5})\s(\w+)\s(\w*)

An example:

   SQL> with t as
      2  ( select 'BLOOKKOKATU 20 A 773 00810 HELSINKI SUOMI' text from dual
      3  )
      4  select text
      5       , regexp_replace(text,'(.*?)\s(\d{5})\s(\w+)\s(\w*)','\1**\2**\3**\4') new_text
      6    from t
      7  /


TEXT
-----------------------------------------
NEW_TEXT
-----------------------------------------------------------------------------------------
BLOOKKOKATU 20 A 773 00810 HELSINKI SUOMI
BLOOKKOKATU 20 A 773**00810**HELSINKI**SUOMI


1 row selected.

Regards,
Rob.