Inserting or deleting records is impossible after sorting SQLQuery:
lazarus / 16-Databases

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salah · 2011-04-27 11:05

Hello,

I created ascending and descending indexes for SQLQuery after opening
it, and I sorted the data by these indexes,
but when I try to post changes after inserting a record the exception
'External: SIGSEGV' is raised.
And when I delete a record, the message 'List index (12) out of
bounds' is displayed.

(I use Lazarus 0.9.30, fpc 2.4.2, FireBird 2.1.3, win XP SP3)

This is the code: (an image of this project is attached)

//////////////////////////////////////////////////////////////////////
////
procedure TForm1.FormCreate(Sender: TObject);
begin
  SQLQuery1.MaxIndexesCount := SQLQuery1.FieldCount * 2 + 2;

  SQLQuery1.Open;
end;

procedure TForm1.SQLQuery1AfterOpen(DataSet: TDataSet);
var
  i: LongInt;
  Field: TField;
  FieldName: String;
begin
  for i := 0 to SQLQuery1.FieldCount - 1 do
  begin
    Field := SQLQuery1.Fields;

    if (Field.FieldKind = fkData) and (Field.DataType in [ftString,
ftDate, ftBCD, ftInteger]) then
    begin
      FieldName := Field.FieldName;

      SQLQuery1.AddIndex(Format('AscIndex%d', ), FieldName, []);
      SQLQuery1.AddIndex(Format('DesIndex%d', ), FieldName,
[ixDescending], FieldName);
    end;
  end;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  SQLQuery1.ApplyUpdates(-1);

  SQLTransaction1.CommitRetaining;
end;

procedure TForm1.DBGrid1TitleClick(Column: TColumn);
begin
  SortDataSet(Column);
end;

procedure TForm1.SortDataSet(Column: TColumn);
var
  Field: TField;
  SQLQuery: TSQLQuery;
  IndexName, AscIndexName, DesIndexName: String;
  IndexDefs: TIndexDefs;
  i, ImageIndex: LongInt;
  IsIndexExist: Boolean;
  DBGridColumns: TDBGridColumns;
begin
  Field := Column.Field;

  if Field = nil then Exit;

  SQLQuery := Field.DataSet as TSQLQuery;

  if SQLQuery.State in [dsInsert, dsEdit] then SQLQuery.Post;

  AscIndexName := Format('AscIndex%d', [Field.Index]);
  DesIndexName := Format('DesIndex%d', [Field.Index]);

  IndexDefs := SQLQuery.IndexDefs;

  IndexDefs.Update;

  for i := 0 to IndexDefs.Count - 1 do
    if (IndexDefs.Name = AscIndexName) or (IndexDefs.Name =
DesIndexName) then
    begin
      IsIndexExist := True;

      Break;
    end;

  if IsIndexExist then
  begin
    IndexName := SQLQuery.IndexName;

    if IndexName = AscIndexName then
    begin
      IndexName := DesIndexName;

      ImageIndex := 1;
    end
    else
    begin
      IndexName := AscIndexName;

      ImageIndex := 0;
    end;

    SQLQuery.IndexName := IndexName;

    DBGridColumns := (Column.Grid as TDBGrid).Columns;

    for i := 0 to DBGridColumns.Count - 1 do
      DBGridColumns.Title.ImageIndex := - 1;

    Column.Title.ImageIndex := ImageIndex;
  end;
end;
//////////////////////////////////////////////////////////////////////
////

Can anyone help me ?

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Lacak2 · 2011-04-28 05:18

And when you do not add indexes (without use "AddIndex") then all
works without any error ?

If yes then it seems like some bug related to indexes used at
TBufDataSet level.
Then if you can provide some reproducible test program, please report
it as bug in bug tracker.