Обсуждение: [Urgent] Regexp_replace question

Hi,

How can I remove characters that form a part of regular expressions? I
would like to remove all instances of the following characters:

[
]
\
+

Given that these all mean something in regexp, I am trying to prefix
them with a backslash, but it doesn't work. I tried the following:

    update TABLE
    set COLUMN = regexp_replace(COLUMN, E'[\\\[\]\+]+', '')
    ;

This did not work so I tried the naked characters separated by a pipe,
as follows:

    update TABLE
    set COLUMN= regexp_replace(COLUMN, E'[\|[|]|+]+', '')
    ;

But this of course did not work either. I've read and re-read the
pattern matching doc page ( http://snipurl.com/pg_regexp ) but it
doesn't seem to offer much help.

Any thoughts on what I am doing wrong?

On Tue, Sep 25, 2007 at 01:36:26PM +0800, Phoenix Kiula wrote:
> How can I remove characters that form a part of regular expressions?

Why do you want to do that?

> I would like to remove all instances of the following characters:
>
> [
> ]
> \
> +

test=> select id, t, regexp_replace(t, e'[\\\\[\\]+]', '', 'g') from foo;
 id |     t      | regexp_replace
----+------------+----------------
  1 | foo[]+\bar | foobar
(1 row)

test=> select id, t, translate(t, e'[]\\+', '') from foo;
 id |     t      | translate
----+------------+-----------
  1 | foo[]+\bar | foobar
(1 row)

--
Michael Fuhr

On 25/09/2007, Michael Fuhr <mike@fuhr.org> wrote:
> > How can I remove characters that form a part of regular expressions?
>
> Why do you want to do that?


Because these values were inserted into the DB due to a faulty
application. So cleansing was called for.

I just ended up doing it with replace instead of regexp_replace, one
character at a time.

Thanks!