Date: Sun, 28 Oct 2007 13:32:54 +0100
From: Andreas Kretschmer <akretschmer@spamfence.net>
To: pgsql-sql@postgresql.org
Subject: Re: Removing whitespace using regexp_replace
Message-ID: <20071028123254.GB17410@KanotixBox>
References: <fg1ra3$ehj$1@ger.gmane.org> <20071028114247.GA1327@KanotixBox>
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Thomas Kellerer <spam_eater@gmx.net> schrieb:

> Andreas Kretschmer wrote on 28.10.2007 12:42:
> >>I have a column with the datatype "text" that may contain leading 
> >>whitespace (tabs, spaces newlines, ...) and I would like to remove them 
> >>all (ideally leading and trailing).
> >You can use trim() for that:
> >select 'x' || trim(both '\t' from trim(both ' ' from ' \t\tfoo bar  ')) 
> >|| 'x';
> >(for testing with 'x' around the result)
> Yes I was thinking about a solution like that as well, but wouldn't that 
> only work if the order in which spaces and tabs appear is always the same?
> The above would replace ' \t' but not '\t ', right?

Oh, yes.


> 
> 
> >For regexp_replace() you need an extra parameter 'g' like below:
> Cool, works like a charm.

Nice, i'm glad to help you.


> But it seems my problem was actually caused by something else:
> 
> SELECT regexp_replace(myfield, '\s*', '', 'g')
> FROM mytable;

you should escape the \, change to ...'\\s*'...

But without anchors this replaces all whitespaces, also within the text
and not only at the beginning/end (^ and $)


Andreas
-- 
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