Re: [Hardhats-members] How to obtain a write access of "~" ?

[Greg Kreis]

Kevin, you have gained good insights into VistA through your dogged exploration of it. Other systems built on a relational database likely have business rules that are not in the database itself, so the business logic is important for maintaining the tables properly. Just going in with a different client and altering the contents of relational tables with SQL could mess up such a system if you happen to operate on some pivotal fields. The key to putting a new face on VistA, it seems to me, is to have well documented interfaces that implement operations that are specified in terms of the domain (i.e. add an Rx, delete a scheduled appt, etc.).  Actually, it seems even better if the granularity of some of these interfaces is small enough to be reused and still efficiently assembled to do the domain specific transactions (like some of the RPCs in VistA). As the VA is doing their re-engineering of parts of VistA, they are having to tease out all the rules and data elements that were implemented in the roll-n-scroll based systems and recast the intent in their new technology. Kevin Toppenberg wrote: It seems to me that VistA is not just a database, with secondarily important routines to adjust that data. Instead, it seems that it is both. Thus this "locked" database field is not supposed to be altered except through the proper channels (the program code.) So it may well be problematic trying to work with the data by circumventing the interaction code. Kevin --- Jim Self <[EMAIL PROTECTED]> wrote: I would appreciate more detailed discussion on this point if possible. It would seem from what you write that such fields cannot be properly edited from the Fileman DBS API. If so, that would seem to present a severe impediment to any attempts to put a more modern general database driven user interface (web or Java or etc) on the affected parts of VistA. [EMAIL PROTECTED] wrote: The use of "^" as a lock is a neat programmer trick to enforce security on a field. It can't be stored in #200 because it will alter the number of pieces in the node (since it is the delimiter, as Kevin noted). It can't even be entered as a lock character through the normal FM field edit functions because it is the "abort" character when entered at a prompt. And even if you set it into your own DUZ(0), FileMan doesn't honor it. The only way to create it is for a programmer to Set it. Of course a programmer could Kill it or change it but that might have unintended consequences. I suspect that there is a considerable amount of processing associated with entering a provider that is hard coded into the routines and a decision was made that it should not be bypassed no matter what the security level of the user. If that is the case, altering ^DD(2,.104,9) would let you use the field through FM but might cause data integrity issues down the road. It would be nice if the Input Transform, the Triggers and all of the other cross references in the DD covered every business rule associated with a field but that is not the case. Some of the rules are so complex and so dependant on the data entry situation that whole sets of routines are required to carry out the appropriate data updates and linkages. tjh --------------------------------------- Jim Self Systems Architect, Lead Developer VMTH Computer Services, UC Davis (http://www.vmth.ucdavis.edu/us/jaself) ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click _______________________________________________ Hardhats-members mailing list Hardhats-members@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/hardhats-members __________________________________ Do you Yahoo!? Meet the all-new My Yahoo! - Try it today! http://my.yahoo.com ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click _______________________________________________ Hardhats-members mailing list Hardhats-members@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/hardhats-members -- Greg Kreis http://www.PioneerDataSys.com "You are today where your thoughts have brought you, you will be tomorrow where your thoughts take you." (James Lane Allen)