InterBase, Delphi5, BDE and Transactions

Hello to everybody!

I´m still trying to use InterBase (really it´s FireBird) with Delphi 5 and BDE but I still have a problem with Transactions.

I really thanks to every one who suggested me things but unfortunately nothing worked.

I tried starting a transaction with another Session component but, as I supposed, it didn´t worked because each transaction is independent of the other (the implicit one made by the BDE and the one I started in another Session).

I tried using CachedUpdates but unfortunately, even in this case, the BDE makes an internal transaction and the problem is the same. I write here my code in case anybody knows I´m doing something wrong.


unit Unit1;

interface

uses
DB,
DBTables,

Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs;

type
TForm1 = class(TForm)
private
{ Private declarations }
public
{ Public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.DFM}

var
DataBaseGeneral : TDataBase;
TablaDeProvincias: TTable;
begin
DataBaseGeneral:=TDataBase.Create(nil);
with DataBaseGeneral do
begin
DataBaseName:='General';
{ DriverName:='INTRBASE';}
AliasName:='MMGeneral';
{ Params.Values['SERVER NAME']:='C:\EGMM\GesCom\General\General.GDB';}
Params.Values['USER NAME']:='SYSDBA';
Params.Values['PASSWORD']:='masterkey';
LoginPrompt:=False;
Connected:=True;
end;

TablaDeProvincias:=TTable.Create(nil);
with TablaDeProvincias do
begin
TableName:='Provinc';
IndexFieldNames:='NOMBRE';
DataBaseName:=DataBaseGeneral.DataBaseName;
CachedUpdates:=True;
Open;

{ DataBaseGeneral.StartTransaction;}
Edit;
TStringField(FieldByName('NOMBRE')).Text:='1'+TStringField(FieldByName('NOMBRE')).Text;
Post;
{ DataBaseGeneral.RollBack;}

DataBaseGeneral.ApplyUpdates([TablaDeProvincias]);
Close;
DataBaseGeneral.Connected:=False;
end;
end.


At the line "DataBaseGeneral.ApplyUpdates([TablaDeProvincias]);" I get the error message "Nested transactions not supported".



I had another idea: starting a transaction directly with an SQL instruction. But I couldn´t do it. My code is:

DataBaseGeneral:=TDataBase.Create(nil);
with DataBaseGeneral do
begin
DataBaseName:='General';
{ DriverName:='INTRBASE';}
AliasName:='MMGeneral';
{ Params.Values['SERVER NAME']:='C:\EGMM\GesCom\General\General.GDB';}
Params.Values['USER NAME']:='SYSDBA';
Params.Values['PASSWORD']:='masterkey';
LoginPrompt:=False;
Connected:=True;
end;

with TQuery.Create(nil) do
begin
DataBaseName:=DataBaseGeneral.DataBaseName;
SQL.Clear;
{ SQL.Add('SET TRANSACTION TransactionMM'+SinEspacios(SinAcentos(NombreDelSistema))+SinEspacios(SinAcentos(NombreDeLaComputadora)));
SQL.Add('NO WAIT ISOLATION LEVEL READ COMMITED NO RECORD_VERSION');}
{ SQL.Add('SET TRANSACTION NO WAIT ISOLATION LEVEL READ COMMITTED NO RECORD_VERSION');}
SQL.Add('SET TRANSACTION');
ExecSQL;
Free;
end;

At the instruction "ExecSQL" I get an error message "General SQL Error. invalid transaction handle (expecting explicit transaction start)". Can anybody tell me what´s wrong in what I´m doing?


Gustavo
gusm@...


[Non-text portions of this message have been removed]