Hi all,
I tried reviewed the code and commented the try...except statement
for more debug:
procedure TfrmMainWindow.bitBtn1Click(Sender: TObject);
begin
//try
DataModuleConn.openConnection;
DataModuleConn.MySQL55Conn.Transaction :=
DataModuleConn.SQLTransaction;
//DataModuleConn.MySQL55Conn.Transaction.Active:=False;
DataModuleConn.SQLTransaction.DataBase:=DataModuleConn.MySQL55Conn;
DataModuleConn.SQLQuery.DataBase:=DataModuleConn.MySQL55Conn;
DataModuleConn.SQLQuery.Transaction:=DataModuleConn.SQLTransaction;
DataModuleConn.SQLQuery.Active:=False;
DataModuleConn.SQLQuery.SQL.Text:='';
DataModuleConn.Datasource.DataSet:=DataModuleConn.SQLQuery;
DataModuleConn.Datasource.DataSet.Active:=False;
//DBGrid1.DataSource.DataSet.Active:=False;
DBGrid1.DataSource:=DataModuleConn.Datasource;
DBNavigator.DataSource:=DataModuleConn.Datasource;
if DataModuleConn.MySQL55Conn.Connected=True then begin
frmMainWindow.memReports.Append(msgOpeningDB);
frmMainWindow.memReports.Append(msgDBReady);
end;
if (cbbList1.Items[cbbList1.ItemIndex] = 'ALL') then begin
DataModuleConn.SQLQuery.SQL.Text:='SELECT gender, year,
country FROM reiser';
end
else if (cbbList1.Items[cbbList1.ItemIndex] = lisCountry1)
then begin
DataModuleConn.SQLQuery.SQL.Text:='SELECT gender, year,
country FROM reiser WHERE country = ''Dutch Republic''';
end
else //(cbbList1.Items[cbbList1.ItemIndex] = lisCountry3)
begin
DataModuleConn.SQLQuery.SQL.Text:='SELECT gender, year,
country FROM reiser WHERE country = ''Holland''';
end;
//DataModuleConn.SQLTransaction.StartTransaction;
DataModuleConn.SQLQuery.Close;
DataModuleConn.Datasource.DataSet.Active:=True;
DataModuleConn.SQLQuery.Open;
//except
// frmMainWindow.memReports.Append(ErrConnectionFailed);
//end;
end;
The first trigged for the procedure bitBtn1Click1 works fine, the
second trigged give up, with the above error:
Operation cannot be performed on an active dataset.
Could you point out which line generates the error ?
As a matter of fact, there are too much DB related operations.
For instance the first 9 lines after the one // Try should be moved
somewhere in an independent method and called only once in some
intialization routine.
Secondly, the two next lines do exactle the same thing, only one of
them should be removed
DataModuleConn.Datasource.DataSet.Active:=True; <====
keep this one as more datasource independent
DataModuleConn.SQLQuery.Open;
<---------- this one can be removed
This rearrangement should work provided the 9 preceeding lines have
been moved somewhere else and executed at least once
if DataModuleConn.SQLQuery.Active then
DataModuleConn.SQLQuery.Close;
if DataModuleConn.MySQL55Conn.Transaction.InTransaction then
DataModuleConn.MySQL55Conn.Transaction.Commit;
if DataModuleConn.MySQL55Conn.Connected=True then begin
frmMainWindow.memReports.Append(msgOpeningDB);
frmMainWindow.memReports.Append(msgDBReady);
end;
if (cbbList1.Items[cbbList1.ItemIndex] = 'ALL') then begin
DataModuleConn.SQLQuery.SQL.Text:='SELECT gender, year,
country FROM reiser';
end
else if (cbbList1.Items[cbbList1.ItemIndex] = lisCountry1)
then begin
DataModuleConn.SQLQuery.SQL.Text:='SELECT gender, year,
country FROM reiser WHERE country = ''Dutch Republic''';
end
else //(cbbList1.Items[cbbList1.ItemIndex] = lisCountry3)
begin
DataModuleConn.SQLQuery.SQL.Text:='SELECT gender, year,
country FROM reiser WHERE country = ''Holland''';
end;
DataModuleConn.SQLTransaction.StartTransaction;
DataModuleConn.SQLQuery.Open;
Antonio.
Press OK to ignore and risk data corruption.
Press Cancel to kill the program.
I tried to close and open the Dataset on my procedure
bitBtn1Click1.
May you please assist me?
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Antonio
Fortuny
Senior Software engineer
220, avenue de la Liberté
L-4602 Niederkorn
Tel.: +352 58 00 93 - 93
www.sitasoftware.lu
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