From: "J. T. Vermeulen" <jtv@cistron-office.nl>
Date: Fri, 30 Mar 2001 14:24:45 +0200
To: Shane Hansen <sl1fm@cc.usu.edu>
Cc: pgsql-interfaces@postgresql.org
Subject: Re: c++ compile/link problem
Message-ID: <20010330142445.G5047@cistron.nl>
Mail-Followup-To: Shane Hansen <sl1fm@cc.usu.edu>,
	pgsql-interfaces@postgresql.org
References: <003601c0b8e3$b2693460$61e97b81@usu.edu>
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	from sl1fm@cc.usu.edu on Thu, Mar 29, 2001 at 11:36:05PM -0700

On Thu, 29 Mar 2001, Shane Hansen wrote:

> I am struggling trying to get a connection to my postgres database from a c++ program.  I have read the documention and looked at many examples, but when I try to compile the code I get the same type errors every time.  They look like:
> 
> /tmp/cc38u8Jz.o: In function `main':
> /tmp/cc38u8Jz.o(.text+0x3b): undefined reference to `PgConnection::PgConnection(
> char const *)'
> /tmp/cc38u8Jz.o(.text+0x4e): undefined reference to `PgConnection::~PgConnection
> (void)'
> collect2: ld returned 1 exit status
> 
> What am I doing wrong?

I'm assuming you've remembered to link to libpq++ here.

This may be a problem with your C++ compiler.  Different compilers, and in some
cases even different versions of the same compiler, mangle C++ identifiers
differently so they won't link to each other's code (and before you ask: yes,
there are good reasons for this--see the C++ FAQ :-).

Have you made sure your version of libpq++ was build with the same compiler?


Jeroen