Message-ID: <442CC95C.1030700@bankir.ru>
Date: Fri, 31 Mar 2006 10:17:00 +0400
From: "Eugene E." <sad@bankir.ru>
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To: Peter Eisentraut <peter_e@gmx.net>
CC: Achilleus Mantzios <achill@matrix.gatewaynet.com>,
	pgsql-sql@postgresql.org
Subject: Re: have you feel anything when you read this ?
References: <Pine.LNX.4.44.0603201522410.22894-100000@matrix.gatewaynet.com>
	<441EA0A7.8030601@bankir.ru> <200603201415.30719.peter_e@gmx.net>
In-Reply-To: <200603201415.30719.peter_e@gmx.net>
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Peter Eisentraut wrote:
> Eugene E. wrote:
> 
>>the problem is: you'll get this four byte sequence '\000' _instead_
>>of NUL-byte anyway.
> 
> 
> What you seem to be missing is that PostgreSQL data can be represented 
> in textual and in binary form.  What you in psql is the textual form.  
> If you want the binary form you need to select it.  Then you can pass 
> the exact bytes back and forth.

your sentence is not true.
I can not select exact bytes even if i use BYTEA type

the folloiwing tiny C-program shows this pretty clear

#include <stdlib.h>
#include <stdio.h>
#include "libpq-fe.h"


int
main (void)
  {
   PGconn   * conn;
   PGresult * res;
   char     * val;
   char     *   l;
   int        len;


   conn = PQconnectdb("user=scott password=tiger dbname=test_db");

   PQexec(conn, "CREATE TABLE t (a BYTEA)");
   PQexec(conn, "INSERT INTO t VALUES ('ab\\\\000cd')");


   res = PQexec(conn, "SELECT a,length(a) FROM t");
   val = PQgetvalue(res,0,0);
   l   = PQgetvalue(res,0,1);
   len = PQgetlength(res,0,0);
   printf("what_we_retrive='%s' its_value_length=%i but 
orig_length=%s\n",val,len,l);

   PQclear(res);
   PQfinish(conn);

   return 0;
  }