On Wednesday 27 January 2010 12:57:20 pm Jacek Kałucki wrote: > Użytkownik John napisał: > > On Wednesday 27 January 2010 12:08:13 pm Paul McNett wrote: > >> On 1/26/10 4:55 PM, Jacek Kałucki wrote: > >>> Użytkownik Paul McNett napisał: > >>>> I missed the "remote user" significance before. > >>> > >>> Oh, second instance of application is enough to see problem. > >> > >> I suppose I could use a second db connection in the test script. > >> > >> Paul > > > > Ok so the remote user deletes all the children. Then won't the > > transaction on the "non" remote user (local user?) fail and rollback. > > After the rollback the local user can then just delete what is available > > - just the parent? > > Question is if there is need to fail if you want delete just deleted data? > Result is the same if you really delete it yourself. > From other side, there is no conflict checking in Dabo at all. > What about save non new data (SQL UPDATE)? > You can save any just remote deleted data without any notice, > unsuccessful of course. > Is such approach correct or not?
Well, for me I have always used a combination of what the DataBase has to offer and preventive programming. In the case of Postgres of course the tools do an excellent job controlling multi-user issues as you describe (constraints, triggers, cascade, etc). And I would expect to see the error and rollback to occur. In the old days with VFP many checks and programming tools were used - including locking records, validation routines, etc.. Today, I believe most (maybe all) the multi-user issues I leave to the database. I just use try:/except: blocks to help. But I allow the database to do most of the job. Johnf _______________________________________________ Post Messages to: [email protected] Subscription Maintenance: http://leafe.com/mailman/listinfo/dabo-dev Searchable Archives: http://leafe.com/archives/search/dabo-dev This message: http://leafe.com/archives/byMID/[email protected]
