[Lazarus] [lazarus] Advice about creating database-aware application with Lazarus

[Howard Lee Harkness]

Guess I'll try 2.2.2rc1, but it looks like in order to do that, I have to
install Lazarus 0.9.25 beta.

Seems to me that I should have been able to get a program as trivial as the
one I am trying to write running with stuff that was available two years
ago. Kinda makes me wonder if I'm just trying to use the wrong tools.

On Thu, Jun 19, 2008 at 8:25 AM, Joost van der Sluis <joost at cnoc.nl> wrote:

> Op zaterdag 14-06-2008 om 19:16 uur [tijdzone -0500], schreef Howard Lee
> Harkness:
> > Did you ever get an answer to this question? I am having a similar
> > difficulty, and information on ApplyUpdates is infuriatingly hard to
> > find.
>
> You can find this problem in the bug-tracker. You can work around it
> with 'TDataset.DisableControls' and 'TDataset.Enablecontrols' around the
> applyupdates call. Or try fpc 2.2.2rc1 or any later version.
>
> Joost.
>
> > On Tue, Oct 10, 2006 at 1:11 AM, Adrian Maier <adrian.maier at gmail.com>
> > wrote:
> >         On 10/10/06, Joost van der Sluis <joost at cnoc.nl> wrote:
> >
> >                 Well... As I read it, that's not the problem. All
> >                 changes are made in an
> >                 update-buffer first. So if you do a 'delete' in the
> >                 grid, the records
> >                 get deleted in that buffer. Thus the record should
> >                 disapear immediately
> >                 in the grid. But not yet on the database.
> >
> >                 The 'delete'-sql is only send to the database on
> >                 the .applyupdates
> >                 command. And committed on the .commitretaining. Thus
> >                 that can happen
> >                 much later. (on the click on the 'save' button)
> >
> >                 But if I understood you correctly, the delete fails
> >                 immediately. That
> >                 means that there's a problem in the deletion of
> >                 records in a grid. Or in
> >                 the .delete from Tbufdataset. You first have to test
> >                 that. Easiest way
> >                 is to add a button 'delete' which does
> >                 sqlquery1.delete. That'll delete
> >                 the current record, and it should be immediately
> >                 visible in the grid.
> >                 Else you could do a .refresh after the .delete, to be
> >                 sure that the grid
> >                 gets refreshed. (If not, it's a bug, btw)
> >
> >
> >         I've added a button which calls query1.Delete.  The row
> >         disappears
> >         from the grid now.     So, it looks like TdbNavigator's
> >         "Delete" button does
> >         something different than it's supposed to do ?
> >
> >         However, when I press "Save" (which does applyupdates and
> >         commitretaining)
> >         the program crashes with  :
> >
> >         TApplication.HandleException Access violation
> >          Stack trace:
> >          $08211A8E
> >          $0821AE3F  TCUSTOMDBGRID__UPDATESCROLLBARRANGE,  line 1336 of
> >         dbgrids.pas
> >          $0821B013  TCUSTOMDBGRID__DOLAYOUTCHANGED,  line 1402 of
> >         dbgrids.pas
> >          $0821CB35  TCUSTOMDBGRID__ENDLAYOUT,  line 2164 of
> >         dbgrids.pas
> >          $0821B660  TCUSTOMDBGRID__LAYOUTCHANGED,  line 1568 of
> >         dbgrids.pas
> >          $08219DA2  TCUSTOMDBGRID__ONDATASETCHANGED,  line 814 of
> >         dbgrids.pas
> >          $0821E518  TCOMPONENTDATALINK__DATASETCHANGED,  line 2722 of
> >         dbgrids.pas
> >          $0820E0F4
> >          $0820EEF5
> >          $0820F10B
> >          $08202E6B
> >          $08205F5D
> >          $08211320
> >          $08211264
> >          $0807DE10  TFORMASIMPLA__ACTIONCOMMITEXECUTE,  line 85 of
> >         forma_simpla.pas
> >          $0808DDB5
> >          $081755F2  TCONTAINEDACTION__EXECUTE,  line 110 of
> >         ./include/containedaction.inc
> >
> >         In ContainedAction.inc:
> >
> >         function TContainedAction.Execute: Boolean;
> >         begin
> >          Result := (ActionList <> nil) and
> >         ActionList.ExecuteAction(Self)
> >           or ((ApplicationActionComponent<>nil)
> >                and ApplicationActionComponent.ExecuteAction(Self))
> >           or inherited Execute                         //
> >         <------------------------- line 110
> >           or (SendApplicationMessage(CM_ACTIONEXECUTE, 0,
> >         PtrInt(Self)) = 1);
> >         end;
> >
> >
> >         Cheers,
> >         Adrian Maier
> >
> >
> >
> >         _________________________________________________________________
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> >                       "unsubscribe" as the Subject
> >          archives at http://www.lazarus.freepascal.org/mailarchives
> >
> >
> >
> >
> > --
> > Howard Lee Harkness
> > _______________________________________________
> > Lazarus mailing list
> > Lazarus at lazarus.freepascal.org
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> --
>
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-- 
Howard Lee Harkness
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