Simon, I thought on the idea of adding a MySQL temp table to manage insert/ del/update on multiple tables. But there would be a large no. of such forms requiring this functionality. It is better to avoid fiddling with the schema (which is the database- tier) for the sake of business-logic tier.
What if I add a temporary table in DAL itself (along with the other linked tables)? Would it break the web2py logic of generating, validating, and saving the form (if this table is used for generating the form)? I mean, if a form is generated from such a temp DAL table, whether it is possible to save data in multiple different tables. ---Vineet ============================================ On May 16, 4:33 pm, Simon Ashley <gregs...@gmail.com> wrote: > Memory tables referred to have no ability to write to disk. Generally > we've used these for report accumulations. You could use a MySQL table > and delete the record at the end (if need be). Crude and there should > be a more pythonic method, but should work. > > Define temp table fields as per the following: > > 1. rec id > 2. table1.uid > 3. table1.variable > 4. table2.uid > 5. table2.variable > 6. table3.uid > 7. table3.variable > > Populate the fields before the load. The uids will of course be hidden > on the form but used after the submit in separate database actions. > > Zero uid's would trigger inserts, > 0 for deletions where variables > are blank or zero, edits where not. There is a level of programming > involved; Massimo implied that. > > In your case, I would be reluctant to denormalise as further > complexity could be cumbersome. > (if not unworkable. Can think of examples in an application that we > are looking at converting that would make anyone's mind spin). > > YMMV > > On May 16, 1:15 am, Vineet <vineet.deod...@gmail.com> wrote: > > > > > > > > > Simon, > > That is a good idea. > > In fact, almost the same approach is being followed in VFP cursor > > adaptor (the difference being that, data from MySQL tables is > > reproduced in same table structures, i.e cursors). > > > Here, by virtual table, do you mean to say that we should reproduce > > the data into dictionaries by fetching a dict cursor from MySQLdb? > > (in DABO, they have an excellent concept of bizobj for this task). > > > I am not asking for exact code, but can you suggest an approach to > > tackle the task? > > > Dear Massimo & other friends, > > can you pl. suggest something to solve my problem? > > > Thanks, > > Vineet. > > > ================================================================= > > On May 15, 5:07 pm, Simon Ashley <gregs...@gmail.com> wrote: > > > > Since no one has replied for a couple of days, I'll toss my 2 cents > > > in. Don't how much value this could be, as we just evaluating web2py > > > and python but in another environment we could have written data in > > > the normalised records to a temporary record in a denormalised, > > > virtualtable, update and saved this record, and then do selective > > > updates, insertions and deletions on each normalised record in the > > > original tables. Not that elegant but ... > > > > On May 13, 9:17 pm, Vineet <vineet.deod...@gmail.com> wrote: > > > > > pbreit, > > > > As you say, wherever possible or required, I have already denormalized > > > > thetable-structures. > > > > Apart from normalization / denormalization issue, in many other forms, > > > > I need to insert/update/delete records inmultipletables from one > > > > form. > > > > (as I mentioned earlier, there will be a mix of insert/update/delete > > > > of record(s) in different tables.) > > > > > Massimo, > > > > If you too haven't understood what I intend to do with these 5 tables, > > > > I can elaborate the idea. > > > > Pl. tell me accordingly. > > > > The very success of developing my project using web2py hinges on this > > > > functionality. > > > > > ---Vineet > > > > ================================================ > > > > > On May 11, 5:17 am, pbreit <pbreitenb...@gmail.com> wrote: > > > > > > Normalizing is not always the best approach. If the database has not > > > > > yet > > > > > been designed, perhaps reconsider. I still don't really understand > > > > > what you > > > > > are trying to do but 5 small tables might not be necessary. > > > > > > I would suggest getting some code working with 2 tables an then go > > > > > from > > > > > there. > > > > > > Some > > > > > options:http://web2py.com/book/default/chapter/07#One-form-for-multiple-table... > > > > > > Another approach would to use FORM or SQLFORM.factory and then coding > > > > > the > > > > > database updates. You lose some of the Web2py features but it might > > > > > still be > > > > > the easiest way to do it. > > > > > > But my first suggestion would be to try and simplify what you are > > > > > intending > > > > > to do.
