Don - the recursive link is really very, very neat and efficient. Once you get the hang of it you'll never go back.
Don (Friedman) Pittsburgh On 4/16/07, Don Codling <[EMAIL PROTECTED]> wrote:
April 16, 2007 Thanks Brian. I was all set to miss the problem with auto increment fields. I shall have to explore the alternative. Don Codling WP 12.0.0.602 DP 2.6x Windows XP home, SP2 512 MBytes RAM Brian Hancock wrote: > Hi, > > The STR file can be modified and program updates distributed via a > portable "STR" within certain boundaries. > > You cannot make a change to the STR which would change the layout of > the data files, ie the tables, so anything which adds, removes or > changes the Field Format on a panel, should not be done using the > portable STR. If you need to change these then you need to export the > data out when the changes is made and reimport after the change. > > If you use :I incrementing number fields then updating an STR will be > a problem, as the STR file holds the value for the next record. If you > want your application to have a "portable" STR then you need to > replace all the :I field, with a technique described in Ralph Alvy' > book about using Recursive Panel Links for producing an incrementing > number... (The concept is simple you link a panel back to itself, and > by using a reversed index, when traversing the link you arrive at the > highest used incrementing number, you can add back your increment > using a formula through that link to increment the counter for the > newly created record). As an aside, using the recursive link for > numbering give a lot more flexibility, as you can choose the increment > or decrement value, or you can create complex incrementing number > patterns which can include alpha characters. One which I use alot is > an incrementing number with a generated check digit, so I might have a > sequece 0016, 0021, 0037,0049 where first 3 digits are the > incrementing number and the the final digit is a check digit > > On the other hand you can use a "portable" STR to change field > formulae, link definitions, reports, colours, etc. If you change an > index, then you need to "bed" the new STR in by starting it with an > Index all (the easiest way to do that, is as soon as you have updated > the STR, start the updated application with the /IND startup switch. > > For the web application work I am now doing with DP, most of the > application logic is in reports, and changing reports with a portable > STR is a piece of cake, providing you do not have :I incrementing > number fields. > > I saw a complaint that DP forces you to empty data from the database > before you can make a change to the data structure, with the > implication that other products do not work that way. I think that > most products do empty the data first, it is just that the application > interfaces usually do that step for you without you knowing, by > creating a copy of the new structure and then copying the old records > back into the new one, then deleting the old and renaming the new. > There are very few database management systems which permit a totally > on-the-fly change to the data structures, and I think they all need > exclusive access by the definer for that time that the conversion is > taking place. > > Regards > Brian > > > > > ----- Original Message ----- From: "Don Codling" > <[EMAIL PROTECTED]> > To: "Dataperfect Users Discussion Group" <[email protected]> > Sent: Monday, April 16, 2007 11:13 AM > Subject: Re: [Dataperf] Modifying structure file > > >> April 15, 2007 >> >> Thank you all. I see I can't change indexes, but the other things I'm >> interested in can be done without a problem. I appreciate the help. >> >> Don Codling >> WP 12.0.0.602 >> DP 2.6x >> Windows XP home, SP2 >> 512 MBytes RAM >> >> Bill Richardson wrote: >>> ** Reply to note from Don Codling <[EMAIL PROTECTED]> Sun, 15 >>> Apr 2007 20:53:58 -0300 >>> | Can I make those kinds of changes in a client's database by giving >>> the >>> | client a modified Structure (.str) file to replace the existing one? >>> | That is, can I make the changes on a copy of the database on my >>> | computer, & simply replace that one file in the client's database? Or >>> | is it necessary to replace all of the client's files even for such >>> | changes? | | If I can just change the structure file, I can add >>> reports, change >>> | colours, etc, for a client, without interrupting his use of his >>> | database & its data. >>> Check out Mastering DataPerfect, pages 418 and following. It's not a >>> simple answer. >>> >>> Bill >>> >>> >>> >>> -------------------------------------------- >>> * Wm. W. Richardson * >>> * Phone: 903/893-0506 * >>> * FAX: 903/893-7890 * >>> * Running at Warp speed under OS/2 * >>> -------------------------------------------- >>> _______________________________________________ >>> Dataperf mailing list >>> [email protected] >>> http://lists.dataperfect.nl/mailman/listinfo/dataperf >>> >>> >> _______________________________________________ >> Dataperf mailing list >> [email protected] >> http://lists.dataperfect.nl/mailman/listinfo/dataperf >> > > _______________________________________________ > Dataperf mailing list > [email protected] > http://lists.dataperfect.nl/mailman/listinfo/dataperf > _______________________________________________ Dataperf mailing list [email protected] http://lists.dataperfect.nl/mailman/listinfo/dataperf
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