Matches from regular expression into collection

Question

Hello,
I need to do the following:
I have a long string with some similar repeated data. I would like, using a regular expression, to extracts all matches in a collection. Is there a way of performing this task?
I have look through the owa_pattern package, but as far as I found out, I can extract only a simple match. Here is an exact quote:
"If multiple overlapping strings can match the regular expression, this function takes the longest match. " - http://download.oracle.com/docs/cd/B28359_01/appdev.111/b28419/w_patt.htm
So what can I do if I want to get all the matches?
Thank you in anticipation. Any help would be appreciated.
Best regards,
beroetz

Answer 1

I think your need a tokenizer-function.
If the string +:in_str+ is delimited by +:in_delimiter+ you could try this:
SELECT REGEXP_REPLACE(REGEXP_SUBSTR( :in_str || :in_delimiter, '(.*?)' || :in_delimiter, 1, LEVEL ), :in_delimiter, '') TOKEN
BULK COLLECT INTO :my_nested_table
FROM DUAL
CONNECT BY REGEXP_INSTR( :in_str || :in_delimiter, '(.*?)' || :in_delimiter, 1, LEVEL ) > 0
ORDER BY LEVEL ASC;
I wrote a string-to-textarray-tokenizer (and it's pendant) some times ago, being able to cut from certain positions within the string using regular expressions and return the elements into an nested table of varchar2. It looks like:
TYPE pos_arraytype IS TABLE OF POSITIVE ;
TYPE text_arraytype IS TABLE OF VARCHAR2(2000);
FUNCTION stringToTextarray(in_str IN VARCHAR2, in_pos_arr IN pos_arraytype, in_regexp_arr IN text_arraytype DEFAULT NULL, in_trim_strings IN BOOLEAN DEFAULT TRUE)
RETURN text_arraytype ;
in_str is the string to be tokenized
in_pos_arr is a table of positive values of positions in the string to be cut
in_regexp_arr is a table of regular expressions to use at each position declared by in_pos_arr
in_trim_strings is a flag, if the cutted element should be trimmed
using above for example:
in_str = 'Markus van Muster 347651234XY Musterdaam ABCDE'
in_pos_arr = (1, 13, 35, 35, 42)
in_regexp_arr = ('(.?){12}', '([^[:digit:]]?){22}', '[[:digit:]]{4}', '[[:alpha:]]{2}', '(.?){14}')
in_trim_strings = TRUE
RETURN collection ('Markus','van Muster','1234','XY','Musterdaam')
If you need the code, then tell me! I'm looking for....
Cheers,
Martin
Edited by: Nuerni on 17.10.2008 08:49