SQLite connection inactive
lazarus / 16-Databases

----------------------------------------------------------------------
SteveF · 2009-03-25 19:52

The following code uses TSQLite datasets to build & activate table in
a SQLite file.  This is an altered version of the TSQLite dataset
tutorial available at
http://www.geocities.com/camara_luiz/docs/dataset/dataset-
tutorial-01.html

 It used to work – I have a version that will connect to the file
built, and read & write to the tables inside.

Then I foolishly made some changes to the application without saving
off what was working before the change.  When I changed this back to
what I thought they were before, I get the following error:

Project AddressBook raised exception class ‘EdatabaseError’ with
message:
Operation cannon be performed on an inactive dataset.

Obviously, I overlooked something.  Any assistance to get this thing
going again without rebuilding from scratch will be appreciated.

Here’s the code:
===============
Procedure Tform1.Formcreate(Sender: Tobject);
Begin
    ForceDirectories(GetAppConfigDir(False));
  With NamesDS do
  begin
   FileName := IncludeTrailingPathDelimiter(GetAppConfigDir(False)) +
'addressbook.db';
   TableName := 'Names';
   if not TableExists then
   begin
    FieldDefs.Clear;
    FieldDefs.Add('NameID',ftAutoInc);
    FieldDefs.Add('Fname',ftString);
    FieldDefs.Add('Lname',ftString);
    CreateTable;
   end;
   SQL := 'SELECT * FROM Names ORDER BY Lname, Fname;';
   Open;
  end;
  With AddrDS do
  begin
   FileName := IncludeTrailingPathDelimiter(GetAppConfigDir(False)) +
'addressbook.db';
   TableName := 'Addresses';
   if not TableExists then
   begin
    FieldDefs.Clear;
    FieldDefs.Add('AddrID',ftAutoInc);
    FieldDefs.Add('NameID',ftInteger);
    FieldDefs.Add('AddrType',ftString);
    FieldDefs.Add('Company',ftString);
    FieldDefs.Add('Address',ftString);
    FieldDefs.Add('Town',ftString);
    FieldDefs.Add('State',ftString);
    FieldDefs.Add('ZIP',ftString);
    FieldDefs.Add('Nation',ftString);
    CreateTable;
   end;
   Open;
  end;
  With PhonesDS do
  begin
   FileName := IncludeTrailingPathDelimiter(GetAppConfigDir(False)) +
'addressbook.db';
   TableName := 'Phones';
   if not TableExists then
   begin
    FieldDefs.Clear;
    FieldDefs.Add('PhoneID',ftAutoInc);
    FieldDefs.Add('NameID',ftInteger);
    FieldDefs.Add('PhoneType',ftString);
    FieldDefs.Add('Number',ftString);
    CreateTable;
   end;
   Open;
  end;
  With wwwDS do
  begin
   FileName := IncludeTrailingPathDelimiter(GetAppConfigDir(False)) +
'addressbook.db';
   TableName := 'WWW';
   if not TableExists then
   begin
    FieldDefs.Clear;
    FieldDefs.Add('wwwID',ftAutoInc);
    FieldDefs.Add('NameID',ftInteger);
    FieldDefs.Add('wwwType',ftString);
    FieldDefs.Add('wwwData',ftString);
    CreateTable;
   end;
   Open;
  end;
End;

===============

TIA,
Steve

----------------------------------------------------------------------
Loesje · 2009-03-27 13:05

Try to find out on which line the problem occurs.

----------------------------------------------------------------------
SteveF · 2009-03-28 20:17

I will see if I can identify the specific line; the problem is that
the application compiles successfully without errors, but the
application does not display data that I know is present in the SQLite
tables (and displays in the "old" version that was built before I
tried to "improve" it.
 
When I click a button on the form to add a new record to the (main)
names table, I receive the error message quoted above.

Steve

----------------------------------------------------------------------
LuizAmérico · 2009-03-29 19:46

To know why the data is wrong, retrieve the value of
GetAppConfigDir(False) (Hint/Quick Hack: set it to the Caption
property) and see if the file that resides there is what you are
expecting. Replace by the correct version if is the case. BTW:
changing the executable name also changes this directory.

The error after pressing the button is caused because the Dataset is
not open. Get the name of the dataset inside the Button handler and
see if is open in the Form.OnCreate handler or if is closed elsewhere.