Subject Re: can I use a CDM the same way as I use a DMD? From Ken Mayer <dbase@nospam.goldenstag.net> Date Fri, 25 Sep 2020 06:09:55 -0700 Newsgroups dbase.getting-started On 9/24/2020 9:13 PM, Gaetano wrote: > > Hi All, > > I have a CDM that only instantiates a database and a couple of functions > for the rest of the app modules to inherit and use.. > > Can I use is as a regular DMD, e.g. > > SET PROC to baseSO2dev.CDM addi > oDMD = new BaseSO2devCDATAMODULE() > > cSQL="truncate table energydata_temp" > oDMD.SO2ADO1.executeSQL(cSQL) You are meant to use a CDM as the basis for other DMD files, just like you cannot run a custom report or a custom form ... > This is to keep the database connectivity details into once central and > compiled file for easier maintenance and security bonus. > > It seems to be working but the Help entry for custom classes says: > > You can’t run a file you’ve developed in this way; it is simply a > template from which other forms, reports, or data modules can be derived. Exactly. > I suspect this means that you can't double-click on them and see the > resulting rowset if a rowset is part of the CDM, but I'd like to make > sure before I hit a wall down the track... It's not the best design, and it sets you up for some bad programming habits. Create a dmd that uses the cdm file and you can then drag that to a form or report in the designer and it will work fine. Ken -- *Ken Mayer* Ken's dBASE Page: http://www.goldenstag.net/dbase The dUFLP: http://www.goldenstag.net/dbase/index.htm#duflp dBASE Books: http://www.goldenstag.net/dbase/Books/dBASEBooks.htm dBASE Tutorial: http://www.goldenstag.net/dbase/Tutorial/00_Preface.htm