FreeTDS Development Group

[Frediano Ziglio <freddyz77 AT tin.it>]

Il giorno dom, 29/01/2006 alle 10.08 +1100, James Harper ha scritto:
> > Hi James,
> > 
> > You've done a bunch of work, and I'd like to see it included in the
> main
> > distribution.  The server code has a few possible uses, not least of
> which
> > is to create a TDS front end to other databases.  Or, as perhaps you
> are
> > doing, non-databases.  The population of interested parties may be
> small,
> > but you're certainly not alone.
> > 
> > It would be great, if you're up for it, to preserve the 4.2 capability
> and
> > add 7.0 (and/or 8.0) to the mix.  The reason to keep 4.2 is that it's
> more
> > similar to 5.0, which is what Sybase uses.  Moving to 7.0-only would
> > exclude the use of Sybase clients, whereas a 4.2 server (as you found)
> is
> > accessible by both vendors' clients.
> > 
> > If you would provide a patch that adds 7.0 capability, I would be very
> > pleased to apply and acknowledge it.
> 
> That's enough incentive then. I was planning on putting it in a patch if
> anyone was interested.
> 
> What I'm actually trying to do is provide a tds proxy to a postgresql
> backend, but if there is even a hint of interest in another backend (eg
> mysql) then I'll try and make it a bit flexible...
> 

Awesome !!!

> It works currently but only for char and varchar types, and only if you
> submit postgresql queries. Once I have the queries working properly I
> plan to write a parser to convert PostgreSQL queries to T-SQL on the
> fly.
> 

Perhaps you should convert T-SQL to PostgreSQL (I think was only a
mistake).

> Ultimately I'd like to take an application that is written for Microsoft
> SQL Server and make it run against PostgreSQL without any modification.
> A few hurdles to overcome before that though.
> 
> What I've found so far is that the code in src/server/ is horribly out
> of date and (at least for what I wanted to do) broken. Not too hard to
> fix though, and maybe only broken because of other changes to the client
> code.
> 

Agreed.

> How would the freetds community feel if I submitted patches that changed
> the client side to better accommodate the server side? One thing I found
> is that the code in src/server tries to use a resinfo structure to
> extract the column info out of, and to send row data, but with one char
> * field containing all the row data it seems like a huge waste to
> assemble your row data into that format (taking into account offsets

True for 0.64

> etc), just so that tds_send_row can disassemble it again to put it into
> the wire. Much better for the server code to have a per column data
> pointer.
> 

True for CVS HEAD :)
I hope you are using CVS, not 0.63/0.64...

> Another thing is there are a bunch of functions associated with finding
> out if a field is fixed, nullable, etc. These would need to be a bit
> more precise to be properly useful for server code.
> 

There are some macros to check nullable, fixed and similar and some
functions to get size, get nullable type from fixed one and vice-versa

> I'll try and send a patch through shortly, or at least within a week.
> 

So we will look forward for your patch.

freddy77