how to export a ADO Dataset to a Comma Separated Values file
with a few lines of code.

procedure TMainForm.SaveDataSetCSV;
const
   adClipString = 2;
   ColumnDelimiter = ';';
   RowDelimiter = #13#10;
var
   s : String;
   fs : TFileStream;
begin
   SaveDialog1.DefaultExt := '.CSV';
   // build the default filename
   SaveDialog1.FileName := ADOTable1.TableName+SaveDialog1.DefaultExt;

   if SaveDialog1.Execute then
   begin
      // Get the complete dataset as CSV
      // the underlying Recordset-Object does the whole work for you
      s := ADOTable1.Recordset.GetString(adClipString, ADOTable1.Recordset.RecordCount, ColumnDelimiter, RowDelimiter, '');

      // save the CSV string to a file
      fs := TFileStream.Create(SaveDialog1.FileName, fmCreate);
      try
         fs.WriteBuffer(s[1], Length(s));
      finally
         fs.Free;
      end;
   end;
end;