Re: Counting Strings

From: Mtek <mtek_at_mtekusa.com>
Date: Wed, 9 Jul 2008 12:12:37 -0700 (PDT)
Message-ID: <4ee38843-024c-44a9-89b0-6f90f0370579@e53g2000hsa.googlegroups.com>


On Jul 9, 1:38pm, "fitzjarr..._at_cox.net" <orat..._at_msn.com> wrote:
> Comments embedded.
>
> On Jul 9, 1:00pm, Mtek <m..._at_mtekusa.com> wrote:
>
> > Hi,
>
> > We are running 10g r2. Too bad REGEXP_COUNT does not work. I need to
> > count the occurances of a string within a string.
>
> > It works from when used in a select from a table:
>
> > SELECT LENGTH(c1) - LENGTH(REPLACE(c1, 'Oracle', 'Oracl')) FROM x;
>
> It works anyway, no matter how you code it. Of course in your first
> example you're making the string shorter by 4 characters:
>
> SQL> create table x(c1 varchar2(25));
>
> Table created.
>
> SQL>
> SQL> insert into x values ('OracleOracleOracleOracle');
>
> 1 row created.
>
> SQL>
> SQL> commit;
>
> Commit complete.
>
> SQL>
> SQL> SELECT LENGTH(c1) - LENGTH(REPLACE(c1, 'Oracle', 'Oracl')) FROM
> x;
>
> LENGTH(C1)-LENGTH(REPLACE(C1,'ORACLE','ORACL'))
> -----------------------------------------------
> 4
>
> SQL>
>
> > This gives me a result of 4, which is correct. However, what if in PL/
> > SQL I need to use it against a variable?
>
> > SELECT LENGTH('ABC:DEF:GAB:CDE:GS') -
> > LENGTH(REPLACE('ABC:DEF:GAB:CDE:GS', ':', 'art')) FROM dual;
>
> > I get -8????
>
> Because you've made the string LONGER by 8 characters, which should
> have been obvious:
>
> SQL> SELECT LENGTH('ABC:DEF:GAB:CDE:GS') from dual;
>
> LENGTH('ABC:DEF:GAB:CDE:GS')
> ----------------------------
> 18
>
> SQL>
> SQL> SELECT
> 2 LENGTH(REPLACE('ABC:DEF:GAB:CDE:GS', ':', 'art')) FROM dual;
>
> LENGTH(REPLACE('ABC:DEF:GAB:CDE:GS',':','ART'))
> -----------------------------------------------
> 26
>
> SQL>
> SQL> SELECT LENGTH('ABC:DEF:GAB:CDE:GS') -
> LENGTH(REPLACE('ABC:DEF:GAB:CDE:GS', ':', 'art')) FROM dual;
>
> LENGTH('ABC:DEF:GAB:CDE:GS')-
> LENGTH(REPLACE('ABC:DEF:GAB:CDE:GS',':','ART'))
> ----------------------------------------------------------------------------
>
> -8
>
> SQL>
>
> Reverse the strings and you'll get a positive value, or use ABS() to
> return the difference:
>
> SQL> SELECT ABS(LENGTH('ABC:DEF:GAB:CDE:GS') -
> LENGTH(REPLACE('ABC:DEF:GAB:CDE:GS', ':', 'art'))) FROM dual;
>
> ABS(LENGTH('ABC:DEF:GAB:CDE:GS')-
> LENGTH(REPLACE('ABC:DEF:GAB:CDE:GS',':','ART'))
> --------------------------------------------------------------------------------
>
> 8
>
> SQL>
>
> > Anyone?
>
> > Thank you,
>
> > John.
>
> David Fitzjarrell

Well, maybe I'm being an idiot, but I want to count the number of occurences of a particular string. So, in the above, the colon is present 5 times. Why do I get 8? Received on Wed Jul 09 2008 - 14:12:37 CDT

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