To: Andy Shellam <andy-lists@networkmail.eu>
cc: pgsql-sql@postgresql.org
Subject: Re: Storing null bytes in bytea 
In-reply-to: <49F5F02A.1070505@networkmail.eu> 
References: <49F5F02A.1070505@networkmail.eu>
Comments: In-reply-to Andy Shellam <andy-lists@networkmail.eu>
	message dated "Mon, 27 Apr 2009 18:49:30 +0100"
Date: Mon, 27 Apr 2009 16:29:09 -0400
Message-ID: <11364.1240864149@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>

Andy Shellam <andy-lists@networkmail.eu> writes:
> Because of the nul bytes, I've set the session_data column to be a bytea 
> column in my database table.  However I cannot get PostgreSQL to read 
> past the first nul byte on an insert, so the unserialize call fails when 
> it reads it back out the database and the remaining data is omitted.

Your example works fine in psql:

regression=# create table t1 (f1 bytea);
CREATE TABLE
regression=# insert into t1 values (E'IsLoggedIn|b:1;CurrentUser|O:17:"Class_SystemUser":4:{s:26:"\\000Class_SystemUser}'::bytea);
INSERT 0 1
regression=# select * from t1;
                                        f1                                      
-----------------------------------------------------------------------------------
 IsLoggedIn|b:1;CurrentUser|O:17:"Class_SystemUser":4:{s:26:"\000Class_SystemUser}
(1 row)


I suspect what is happening is that some layer on the client side is
doubling (or perhaps undoubling?) the backslashes for you.  Exactly
what are you doing with that literal as you build the query?  It might
help to turn on log_statements so that you can see just what the
server is getting.

			regards, tom lane