FreeTDS Development Group

["James K. Lowden" <jklowden AT schemamania.org>]

On Mon, 29 Dec 2003 11:58:20 -0500, christos AT zoulas.com (Christos Zoulas)
wrote:
> | By encoding the NULL specially. Microsoft's bcp works fine. I will
> | check how it encodes it and report back. (Same for native format).
> 
> It encodes the NULL by outputting a length of \xff\xff. We should be
> doing the same.

Right, thanks for checking that out, Christos.  That's a 2-byte -1, as you
know.  Precisely what the TDS protocol uses.  

For native bcp files, I bet all we need is tds_put_packet_to_file(). 
Don't interpret the row image; just grab the buffer and go.  

Sending is a little more work, because we have to allow for the
possibility that the table definition has changed meanwhile.   It's valid
to bcp out a table, alter its datatypes (say, float -> real) and reload
it.  It's db-lib's job to bind and convert the data accordingly.  

Assuming I'm right -- that the bcp native file image mimics the wire image
-- sending may be just a matter of reading rows from a native bcp file in
much the same way we read rows from a socket.  That's not how things are
architected now, but, you know ... live and learn.  

--jkl