REGEXP_SUBSTR() help

Question

Hi:
I've got a bunch of triggers that I'm trying to get rid of. They are BEFORE UPDATE OF x1,x2,x3... triggers and they basically prevent the user from updating the columns. I want to do away with these and make the table declarations handle it (grant select only on the columns not found in the trigger of a given table). So step 1 is I'm trying to go through the user_triggers description column and parse out the columns that the current trigger applies to. I've simplified the example by including text directly into the REGEXP call but I'm really using it in a larger query on user_triggers and the REGEXP is working off of the description column contents.
My problem is that I want a way to extract the columns and only the columns. I currently have:
select upper(REGEXP_SUBSTR(
'TRIGGER "GAFF".access_tbus
   BEFORE UPDATE OF access_code,foo1_col,foo2_col ON access_tbl
BEGIN
   s2_error_pck.update_not_allowed(''Access_TBL column Access_Code, foo1_col, foo2_col'');
END;',
       '(((before update)[ ]{1})'                  -- keywords followed by a space
      || '(\s*[[:alnum:]_]+\s*,){0,10})'        -- 0 to 10 instances of column_name followed by comma
      || '(\s*([[:alnum:]_]\s*).*)',1,1,'i'))     -- the final (perhaps only) column name, not followed by comma
from dualbut the result is
BEFORE UPDATE OF ACCESS_CODE,FOO1_COL,FOO2_COL ON ACCESS_TBLI currently have this working (I think!) with 1-n columns in the list but I get more than I want in the output. How do I user the BEFORE UPDATE OF to match but not include it or the table name in the result? (I'd ideally like to tack on a ' ON ' in the match as well if I can do that but not get stuck with that in the output as well).
Thanks,
Gaff

Answer 1

Hi,
Example:
Connected to Oracle Database 10g Express Edition Release 10.2.0.1.0
Connected as hr
SQL>
SQL> SELECT ut.trigger_name,
  2         ut.trigger_type,
  3         ut.triggering_event,
  4         utc.table_name,
  5         utc.column_name
  6    FROM user_triggers     ut,
  7         user_trigger_cols utc
  8   WHERE ut.trigger_name = utc.trigger_name
  9   ORDER BY ut.trigger_name,
10            utc.table_name,
11            utc.column_name;
TRIGGER_NAME                   TRIGGER_TYPE     TRIGGERING_EVENT                                                                 TABLE_NAME                     COLUMN_NAME
UPDATE_JOB_HISTORY             AFTER EACH ROW   UPDATE                                                                           EMPLOYEES                      DEPARTMENT_ID
UPDATE_JOB_HISTORY             AFTER EACH ROW   UPDATE                                                                           EMPLOYEES                      EMPLOYEE_ID
UPDATE_JOB_HISTORY             AFTER EACH ROW   UPDATE                                                                           EMPLOYEES                      HIRE_DATE
UPDATE_JOB_HISTORY             AFTER EACH ROW   UPDATE                                                                           EMPLOYEES                      JOB_ID
SQL> Regards,
Edited by: Walter Fernández on Feb 23, 2009 5:13 PM