From: Jasen Betts <jasen@xnet.co.nz>
To: pgsql-sql@postgresql.org
Subject: Re: Regular Expression Match Operator escape character
Date: 13 Dec 2010 09:18:29 GMT
Message-ID: <ie4od5$scs$5@reversiblemaps.ath.cx> (raw)
References: <006601cb96df$0fd82cd0$2f888670$@com>
On 2010-12-08, Gnanakumar <gnanam@zoniac.com> wrote:
> Hi,
>
> We're running PostgreSQL v8.2.3 on RHEL5.
>
> In some places in our application, we use Regular Expression Match Operator
> (~* => Matches regular expression, case insensitive) inside WHERE criteria.
>
> Example:
> SELECT ...
> FROM ...
> WHERE (SKILLS ~*
> '(^|\\^|\\||[^0-9|^a-z|^A-Z]|$)C#(^|\\^|\\||[^0-9|^a-z|^A-Z]|$)'
> OR SKILLS ~*
> '(^|\\^|\\||[^0-9|^a-z|^A-Z]|$).NET(^|\\^|\\||[^0-9|^a-z|^A-Z]|$)')
>
> In this case, we're trying to search/match for either "C#" OR ".NET" in
> SKILLS column.
>
> My question here is, do I need to escape the characters "#" and "." here?
yes. ( '.' especially, I don't think '#' has a special meaning in regex)
but as postgres uses posix extended regex simply escaping every non-letter
character is safe.
(^|\\^|\\||[^0-9|^a-z|^A-Z]|$)
seems to be another way to write
(^|$|[^0-9a-zA-Z])
both of which are locale dependant but that may not be an issue for you.
--
⚂⚃ 100% natural
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-sql@postgresql.org
Cc: jasen@xnet.co.nz
Subject: Re: Regular Expression Match Operator escape character
In-Reply-To: <ie4od5$scs$5@reversiblemaps.ath.cx>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox