[Lazarus] [lazarus] Advice about creating database-aware application with Lazarus
Howard Lee Harkness
howard.lee.harkness at gmail.com
Sun Jun 22 00:31:09 CEST 2008
Lazarus 9.25 beta (with FPC 2.2.2) does not appear to be ready for prime
time. The first thing it did on my system was crash when I tried to close a
project that partially loaded and quit due to not finding the ZeosLib
components. Then, it failed to rebuild the IDE when I tried to install
ZeosLib.
Guess I need to wait for the real release.
On Sat, Jun 21, 2008 at 5:05 PM, Howard Lee Harkness <
howard.lee.harkness at gmail.com> wrote:
> 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
>> >
>> >
>> >
>> >
>> _________________________________________________________________
>> > To unsubscribe: mail lazarus-request at miraclec.com with
>> > "unsubscribe" as the Subject
>> > archives at http://www.lazarus.freepascal.org/mailarchives
>> >
>> >
>> >
>> >
>> > --
>> > Howard Lee Harkness
>> > _______________________________________________
>> > Lazarus mailing list
>> > Lazarus at lazarus.freepascal.org
>> > http://www.lazarus.freepascal.org/mailman/listinfo/lazarus
>> --
>>
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>
>
>
> --
> Howard Lee Harkness
>
--
Howard Lee Harkness
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