procedure TForm1.ADOTable1BeforePost(DataSet: TDataSet);
var
  dbSL, findSL: TStringList;
  i: integer;
  isOK: boolean;
  filterStr: string;
const
  ORstr: array[boolean] of string = (' OR ', '');
begin
  dbSL := TStringList.Create;
  try
    dbSL.Delimiter := ',';
    dbSL.DelimitedText := DBEdit2.Text;

    findSL := TStringList.Create;
    findSL.Duplicates := dupIgnore;

    isOK := true;
    for i := 0 to dbSL.Count - 1 do begin
      if SL.IndexOf(dbSL.Strings[i]) > -1 then begin
        isOk := false;
        findSL.Add(dbSL.Strings[i]); // Дубликаты игнорируются
      end;
    end;

    if isOK then begin
      for i := 0 to dbSL.Count - 1 do begin
        SL.Add(dbSL.Strings[i]);
      end;
    end
    else begin
      filterStr := '';
      for i := 0 to findSL.Count - 1 do begin
        filterStr := filterStr + ORstr[i = 0] +
          '([txt] LIKE *' + findSL.Strings[i] + '*) ';
      end;
      DataSet.Cancel;

      ADOTable1.Filtered := False;
      ADOTable1.Filter := filterStr;
      ADOTable1.Filtered := True;

      Abort;
    end;
  finally
    dbSL.Free;
    findSL.Free;
  end;
end;