From: | David Wheeler <david(at)wheeler(dot)net> |
---|---|
To: | Tim Bunce <Tim(dot)Bunce(at)pobox(dot)com> |
Cc: | Jeff Urlwin <jurlwin(at)bellatlantic(dot)net>, dbi-dev(at)perl(dot)org, pgsql-interfaces(at)postgresql(dot)org |
Subject: | Re: :PgSQL: More Queestions |
Date: | 2002-11-21 06:30:00 |
Message-ID: | A95C6280-FD1A-11D6-8943-0003931A964A@wheeler.net |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-interfaces |
On Wednesday, November 20, 2002, at 06:53 AM, Tim Bunce wrote:
>> But if I change it (as I'm seriously considering, in light of
>> PostgreSQL 7.3's support for prepared statements), I'll probably do no
>> parsing for comments.
>
> I think that would be a bad move.
Yes, your last post makes very clear why. Thanks.
> If it's seen the start of a string ("..." or '...') then it just
> keeps copying the string till it finds the same type of quote
> character to mark the end of the string. The 'fiddly bit in the
> middle' is handling backslashes used to escape quote chars in the
> middle of the string: "...\"..." and "...\\" (odd vs even number).
Seems rather opaque. Maybe I'm just reflecting my C-newbieness, but why
wouldn't this work as well? Borrowing a bit from DBD::ODBC here (but
allowing for both kinds of escaping of the quote characters):
if (*src == '"' || *src == '\'') {
if (!in_literal) {
literal_ch = *src;
in_literal = 1;
} else {
if (*src == literal_ch && *(src-1) != '//'
&& *(src-1) != literal_ch) {
in_literal = 0;
}
}
}
> ANSI standard doesn't use backslashes, it uses doubling: "...""..."
Yeah, as Rudy pointed out, however, PostgreSQL uses backslashes as well
as doubling.
> Take a look at dbd_preparse in DBD::Oracle.
Will do, when I'm more awake again and find the tuits...
> There's also a preparse() in DBI.xs which was destined to become a
> standard service offered to drivers - but isn't quite ready yet.
Hrm, yes, that could be quite handy, since dbd_preparse() seems to be
one of the more complex driver functions...
Regards,
David
--
David Wheeler AIM: dwTheory
david(at)wheeler(dot)net ICQ: 15726394
http://david.wheeler.net/ Yahoo!: dew7e
Jabber: Theory(at)jabber(dot)org
From | Date | Subject | |
---|---|---|---|
Next Message | Oliver Elphick | 2002-11-21 07:50:03 | Re: DBD::PostgreSQL |
Previous Message | David Wheeler | 2002-11-21 03:09:34 | Re: :PgSQL: More Queestions |