Re: Literal '-' in regular expression bracket sets

On Thu, 5 Sep 2002, Steve wrote:

>
> I'm trying to place a literal '-' in a bracketed character set in a regular
> expression for a check constraint. I am currently escaping it with a '\',
> however, it still winds up in the table definition as a non-literal dash and
> is interpreted as a character range. For instance:
>
> CREATE TABLE retest
> (
>         hostname VARCHAR(100) CHECK (hostname ~ '^[a-zA-Z0-9\-\.]+$' )
> );

I think you might have to move the dash to the beginning of the character
set.  I can't find an easy way to make it happy otherwise. I believe the
'.' doesn't need to be escaped.