RE: MS SQL server access from RPG

I believe there was someone on this list a few months back that said the iSeries DRDA "driver" was what allowed the remote DRDA compliant database (including Informix) to be accessed by the CRTDDMF file so the RPG would still see and use native F specs and opcodes and not even be aware the database was not local. That the DDM-->DRDA---> Informix translated a CHAIN to whatever was needed in DRDA protocol to get the record requested.

-----Original Message-----
From: midrange-l-bounces@xxxxxxxxxxxx [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of CRPence
Sent: Thursday, April 30, 2009 12:45 PM
To: midrange-l@xxxxxxxxxxxx
Subject: Re: MS SQL server access from RPG

Mike Cunningham wrote:

The reason I asked was because we are looking at some ERP
solutions that run on three different databases that might move
our DB2/400 ERP to Informix (DRDA compliant) or MS SQL (not DRDA
compliant). We have lots of in house developed apps that
currently access our DB2/400 ERP. If we went the Informix route
we could simply use DRDA to make the Informix database look like
its local (CRTDDMF pointing to the Informix database). No code
changes needed. The JDBC route would work (we have done this from
some java apps already) but would require some major changes in
the applications to move from an "F" spec file definition with
CHAIN/READ/SETLL etc code to calls to a service program or
embedded SQL. Doable, and maybe a better long term solution, but
a much more costly, time-consuming conversion would be needed. We
are considering asking the vendors to use a DRDA compliant
database or provide as part of their package/support a 3rd party
DRDA gateway that would make MS SQL accessible via DRDA

The programs would still have to replace F-spec with SQL to use
DRDA. Informix probably does not provide DDM access to its data, so
presumably only DRDA will be available to access Informix SQL data;
i.e. via an Informix DRDA server. That is, I think a conversion to
use SQL is going to be required, regardless of which other database
is chosen for the ERP on another platform.

Regards, Chuck