BufferDataset  error Save and Load from file
lazarus / 16-Databases

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eldonfsr · 2024-09-24 01:10

I don't know why now bufferdataset give me error save and load from
file

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paweld · 2024-09-24 05:04

What version of lazarus / fpc? In Lazarus trunk / fpc 3.2-fixes
version the project works fine - when closing the form it saves to
file, when opening it loads from file if file exists

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eldonfsr · 2024-09-24 12:32

windows lazarus 3.2.2 this error show when save..and close buffer data

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rvk · 2024-09-24 12:59

Works fine for me too.

BUT... you shouldn't free mdbtns in your CloseForm !!!!!!!!
The mdbtns is created and controlled (owned) by your form.
NEVER free components that you don't create yourself (with nil as
owner parameter).

This is probably the reason for your error (because TForm is trying to
clear and free the component while you already did so).

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eldonfsr · 2024-09-24 13:45

Yes i remove MDBtns.close and MDBtns.free, but  still send me a error
on close and another this you can see values show me on dbgrid is not
what values i put on fields..
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i Var
ic:Integer;begin   if( not FileExists(GetCurrentDir+'\BTNSMACROS.db'))
then begin     if( MDBtns.Active=false) then begin //    
 MDBtns.FileName:=GetCurrentDir+'\BTNSMACROS.db';//      
MDBtns.LoadFromFile(GetCurrentDir+'\BTNSMACROS.db');     
 MDBtns.Open;       ic:=0;     if MDBtns.EOF then begin     
 MDBtns.Append;       MDBtns.FieldByName('PageNo').AsInteger:= 0;    
 MDBtns.FieldByName('BtnName').AsString:= 'BtnHomeSp1';     
 MDBtns.FieldByName('Caption').AsString:= 'Home';     
 MDBtns.FieldByName('Macro').AsString:= 'MS0';       MDBtns.post;    
 MDBtns.Append;       MDBtns.FieldByName('PageNo').AsInteger:= 0;    
 MDBtns.FieldByName('BtnName').AsString:= 'BtnMovUnoSp1';     
 MDBtns.FieldByName('Caption').AsString:= 'Move 1';     
 MDBtns.FieldByName('Macro').AsString:= 'MS30';       MDBtns.post;   
  MDBtns.Append;       MDBtns.FieldByName('PageNo').AsInteger:= 0;   
  MDBtns.FieldByName('BtnName').AsString:= 'BtnMtoDosSp1';     
 MDBtns.FieldByName('Caption').AsString:= 'Move 2';     
 MDBtns.FieldByName('Macro').AsString:= 'MS35';       MDBtns.post;   
  MDBtns.Append;       MDBtns.FieldByName('PageNo').AsInteger:= 0;   
  MDBtns.FieldByName('BtnName').AsString:= 'BtnMvtCycleSp1';     
 MDBtns.FieldByName('Caption').AsString:= 'Move Cycle';     
 MDBtns.FieldByName('Macro').AsString:= 'MS40';       MDBtns.post;   
  MDBtns.Append;       MDBtns.FieldByName('PageNo').AsInteger:= 0;   
  MDBtns.FieldByName('BtnName').AsString:= 'BtnMvtLoopSp1';     
 MDBtns.FieldByName('Caption').AsString:= 'Loop Cycle';     
 MDBtns.FieldByName('Macro').AsString:= 'MS50';       MDBtns.post;   
  MDBtns.Append;       MDBtns.FieldByName('PageNo').AsInteger:= 0;   
  MDBtns.FieldByName('BtnName').AsString:= 'BtnTechPosi1Sp1';     
 MDBtns.FieldByName('Caption').AsString:= 'Teach Posi 1';     
 MDBtns.FieldByName('Macro').AsString:= 'MS90';       MDBtns.post;   
  MDBtns.Append;       MDBtns.FieldByName('PageNo').AsInteger:= 0;   
  MDBtns.FieldByName('BtnName').AsString:= 'BtnTechPosi2Sp1';     
 MDBtns.FieldByName('Caption').AsString:= 'Teach Posi 2';     
 MDBtns.FieldByName('Macro').AsString:= 'MS95';       MDBtns.post;   
  MDBtns.Append;       MDBtns.FieldByName('PageNo').AsInteger:= 0;   
  MDBtns.FieldByName('BtnName').AsString:= 'BtnSpeedAccSp1';     
 MDBtns.FieldByName('Caption').AsString:= 'Speed Acc';     
 MDBtns.FieldByName('Macro').AsString:= 'MS100';       MDBtns.post;  
   MDBtns.Append;       MDBtns.FieldByName('PageNo').AsInteger:= 0;  
   MDBtns.FieldByName('BtnName').AsString:= 'BtnFindSurfSp1';     
 MDBtns.FieldByName('Caption').AsString:= 'Find Surface';     
 MDBtns.FieldByName('Macro').AsString:= 'MS60';       MDBtns.post;   
 end;    end else begin     
 MDBtns.FileName:=GetCurrentDir+'\BTNSMACROS.db';     
 mdbtns.LoadFromFile(GetCurrentDir+'\BTNSMACROS.db');     
 MDBtns.Open;    end;     end else begin   
 mdbtns.LoadFromFile(GetCurrentDir+'\BTNSMACROS.db' );   
 MDBtns.Open;   end;

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eldonfsr · 2024-09-24 13:48

I download and install lazarus 3.4 still the same problem ....

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rvk · 2024-09-24 13:50

Quote from: eldonfsr on September 24, 2024, 03:45:19 pmYes i remove
MDBtns.close and MDBtns.free, but  still send me a error on
closeDoesn't happen here

Quote from: eldonfsr on September 24, 2024, 03:45:19 pm and another
this you can see values show me on dbgrid is not what values i put on
fields..
You might want to begin with deleting the existing db file because
that code doesn't execute if the file exists.
(And you probably have some fields from before)

This code doesn't correspond with the earlier code so you have changed
things around.
So we can't tell what's going on.

BTW. I wouldn't do MDBtns.FieldByName('PageNo').AsString := '4' since
PageNo is defined as SmallInt.
You might want to use AsInteger instead.
(FPC will convert this but it's better to be sure)

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eldonfsr · 2024-09-24 17:39

I create a new project and send me same error when close app is only
bufferdata and dbgrid on form..
and also the information is now as was insert on fields... some
problems

lazarus 3.4 64 on windows 10

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BrunoK · 2024-09-24 17:51

Quote from: eldonfsr on September 24, 2024, 07:39:55 pmI create a new
project and send me same error when close app is only bufferdata and
dbgrid on form..
and also the information is now as was insert on fields... some
problems

lazarus 3.4 64 on windows 10
All I can add is that I tried the last program (Win 10, FPC 3.2.2, laz
+- trunk) and there are quite a few errors showing as described by
eldonfsr.

I couldn't find what might be wrong to the point of getting all these
errors in his code.

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eldonfsr · 2024-09-24 18:52

I made the same sample on other computer and same results datas not as
was input values and when close app same error...

lazarus 3.4 windows 10...

and i made same test typhon and not problem....

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TRon · 2024-09-24 18:57

Wasn't there an issue with tbufdataset and persistent fields ? e.g.
you had to use createdataset explicitly ? I might remember it wrong
though...

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eldonfsr · 2024-09-24 19:58

Exactly is what i did...

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TRon · 2024-09-24 22:25

Apologies as it took me some time to locate the corresponding thread.

see here, reported at issue  40450 (and seems to have been fixed by
wp).

My mind isn't exactly clear atm so pardon me for not being able to
advise how you need to fix that in your current code.

Perhaps someone else is around is able to help you out.

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eldonfsr · 2024-09-24 22:34

Wow i understand what you sad... i made changes and look working let
me continue with make better understanding this thinks...

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rvk · 2024-09-25 00:45

Quote from: TRon on September 25, 2024, 12:25:41 amsee here, reported
at issue  40450 (and seems to have been fixed by wp).
Which should be fixed in version 3.4, shouldn't it?

Quote from: eldonfsr on September 24, 2024, 08:52:05 pmI made the same
sample on other computer and same results datas not as was input
values and when close app same error...

lazarus 3.4 windows 10...

and i made same test typhon and not problem....
So that version should be ok.

(I'm on the fixes_3_2 version and it worked fine for me so it should
have worked in 3.4 too)

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egsuh · 2024-09-25 03:49

I think the problems come from TFields,

   MDBtnsBtnName
   MDBtnsCaption
   MDBtnsPageNo
   MDBtnsMacro

and so on. When I removed them, all works fine, except saving the
file. 

－－－－－－－－－－－－－

I have dropped all the TFields, and added them again and the program
works fine, including saving the database.

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rvk · 2024-09-25 08:20

Quote from: egsuh on September 25, 2024, 05:49:12 amI have dropped all
the TFields, and added them again and the program works fine,
including saving the database.
Can you compare the lfm (the part with the fields) with the original
one?
I wonder why it would work after that.

(And what version of Lazarus?)

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TRon · 2024-09-25 08:20

Quote from: rvk on September 25, 2024, 02:45:27 amWhich should be
fixed in version 3.4, shouldn't it?
Are you sure that Lazarus 3.4 came with a new(er) version of FPC ? 

I am not sure it made fixes though (and I haven't seen fixes/trunk
mentioned by TS).

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rvk · 2024-09-25 08:24

Quote from: TRon on September 25, 2024, 10:20:09 amQuote from: rvk on
September 25, 2024, 02:45:27 amWhich should be fixed in version 3.4,
shouldn't it?
Are you sure that Lazarus 3.4 came with a new(er) version of FPC ? 

I am not sure it made fixes though (and I haven't seen fixes/trunk
mentioned by TS).
Woops, yes, I meant FPC fixes (the TBufDataset is in FPC, not in Laz).

Last week I tried a new trunk (Laz+FPC) and that failed so I set my
script back at fixes versions.
Code: Text  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i set
fpc_version="fixes_3_2"set laz_version="fixes_3_2a"
That version gave me no problems.

Aren't those (fixes_3_2 and fixes_3_2a) not incorperated in the
Lazarus 3.4 install (for both FPC and Lazarus) ???

Quote from: mattias on May 29, 2024, 09:38:42 amThe Lazarus team is
glad to announce the release of Lazarus 3.4.

This is a bugfix release and was built with FPC 3.2.2.
Aaaaargh. So maybe they are not and FPC still has that problem with
the standard install.

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egsuh · 2024-09-25 08:44

QuoteCan you compare the lfm (the part with the fields) with the
original one?
I wonder why it would work after that.

(And what version of Lazarus?)
I don't see any difference between the two files, except that I've set
the size of field MCode to 20, which is a ftMemo field (in the
original file, it was 0). At first I had the same errors reported, and
I set the size of MCode to 20, and the same errors.
Then I deleted and repopulated all the TFields. Then OK.

Lazarus version is 3.4.

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rvk · 2024-09-25 09:30

Just tried standard 3.4 (my own compile went correctly but I'm not
sure the revert to 3.2.2 went ok).

Standard Laz 3.4 with FPC 3.2.2 is indeed a mess with TBufDataset.

Just removing the MCode (and decoupling the TDBMemo) fixes the startup
problems (without a DB present).

The error for exiting probably has to do with that mentioned issue.
BTW. After starting the application with an existing correct db, the
exit works fine.

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TRon · 2024-09-25 12:11

Quote from: rvk on September 25, 2024, 10:24:07 amWoops, yes, I meant
FPC fixes (the TBufDataset is in FPC, not in Laz).
Thank you for the confirmation (my head is such a mess atm that I
wasn't sure either).

QuoteAren't those (fixes_3_2 and fixes_3_2a) not incorperated in the
Lazarus 3.4 install (for both FPC and Lazarus) ???
Unfortunately, no.

That is why it is such a PITA that the release-cycle of FPC is (so)
much slower (when compared to Lazarus).

QuoteAaaaargh. So maybe they are not and FPC still has that problem
with the standard install.
For sure. Therefor the only person able to shed a light is eldonfsr
(until then I/we have to assume that (s)he is using a standard (non
trunk/fixes) installation, no matter the version)

fwiw: It seems to be such a mess (either code-wise or in my head, not
sure   ) that I do not know how to (correctly) work around the issue
in TS' code.

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rvk · 2024-09-25 12:44

Quote from: TRon on September 25, 2024, 02:11:15 pmfwiw: It seems to
be such a mess (either code-wise or in my head, not sure   ) that I do
not know how to (correctly) work around the issue in TS' code.
Yes, my advise would be to just get rid of the persistent fields (via
the object inspector).
They aren't even used so just remove them. (only use FieldByName, NOT
persistent defined fields.

But leave the FieldDefs in the TBufDataset (they are used for
creation).

Move everything from FormShow to FormCreate (you don't want to be too
late with creating the database).

Last... change the first MDBtns.Open to MDBtns.CreateDataset in
Active=false part (just above the Append).

After that... everything should work fine (even in Lazarus 3.4).

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TRon · 2024-09-26 05:28

Quote from: rvk on September 25, 2024, 02:44:55 pmAfter that...
everything should work fine (even in Lazarus 3.4).
(Again) apologies for the delay.

Thank you very much for those detailed instructions rvk 

That seems to work as intended.... with one small side-note: I needed
to remove the existing db (from the original archive of TS) in order
to prevent a streaming error on startup (which makes perfect sense).

In hind-side the suggested workaround makes perfect sense but this
must be a PITA for those unfamiliar with bufdataset (which includes me
as I hardly use this class/component)

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rvk · 2024-09-26 09:26

Quote from: TRon on September 26, 2024, 07:28:47 amIn hind-side the
suggested workaround makes perfect sense but this must be a PITA for
those unfamiliar with bufdataset (which includes me as I hardly use
this class/component)
I do find it logical that you would need to do a CreateDataset (or
likewise command). But I also normally don't used predefine FieldDefs
in the object inspector. I much more prefer adding the FieldDefs in
code and then a CreateDataset is more intuitive to create the dataset
after defining the fields. And then there is no problem.

Luckily the problem with persistent fields is solved in the next
version.
But I don't like using persistent fields anyway (as I do everything
via code and FieldByName).

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TRon · 2024-09-26 09:36

Amen to/for setting things up manually rvk.

Even though I started out designing databases with the visual designer
(Delphi back then), once you have several forms/modules stuffed to the
brim with database components then things become unmaintainable and is
it much easier to manage manually (especially when you have the GUI
and functional code separated).

Hopefully TS is (now) able to workaround the issue as well (thanks to
your excellent instructions) but even better would be a new release of
the compiler

Again, thank you very much for the guidance rvk.