From: Bruce Momjian <pgman@candle.pha.pa.us>
Message-Id: <200602030355.k133tNw00862@candle.pha.pa.us>
Subject: Re: [BUGS] BUG #2171: Differences compiling plpgsql in ecpg
In-Reply-To: <1138905401.5342.15.camel@swithin>
To: Andrew Dunstan <andrew@dunslane.net>
Date: Thu, 2 Feb 2006 22:55:23 -0500 (EST)
CC: andrew5@ece.cmu.edu, PostgreSQL-patches <pgsql-patches@postgresql.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Content-Type: text/plain; charset=US-ASCII

Andrew Dunstan wrote:
> On Wed, 2006-02-01 at 23:48 -0500, Bruce Momjian wrote:
> > I have researched your report, and you are right, there are two ecpg
> > bugs here.  First, dollar quoting uses single-quotes internally to do
> > the quoting, but it does not double any single-quotes in the
> > dollar-quoted string.
> > 
> 
> As a matter of curiosity, why does ecpg handle dollar quoting like that?
> psql, for example, happily just passes a dollar quoted string through to
> the backend, without any need to convert it to a conventionally quoted
> string.

ecpg actually parses the statements so it can do things like make
variable substitutions.  The $$ and '' strings are actually passed to
preproc.y as SCONST.  parser/scan.l does the same thing, though it
doesn't need to single-quote it and pass it up to eventually be output
in C.

-- 
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 359-1001
  +  If your life is a hard drive,     |  13 Roberts Road
  +  Christ can be your backup.        |  Newtown Square, Pennsylvania 19073