uses StrUtils;
...

function  DecodeConnectString(const S: string; var Username, Password, Database, ConnectAs	: string): Boolean;
var i, Mode: Integer;
    InQuotes, ModeChange: Boolean;
    ws: widestring;
begin
  ws := s;
  Mode := 0;
  InQuotes := False;
  if ws = '' then
  begin
    ws := Username;
    if Password <> '' then ws := ws + '/' + Password;
    if Database <> '' then ws := ws + '@' + Database;
    if ConnectAs <> '' then ws := ws + ' as ' + ConnectAs;
  end;
  Username := '';
  Password := '';
  Database := '';
  ConnectAs := StripConnectAs(ws);
  for i := 1 to Length(ws) do
  begin
    if ws[i] = '"' then InQuotes := not InQuotes;
    ModeChange := False;
    if (not InQuotes) then
    begin
      if (Mode < 1) and (ws[i] = '/') then
      begin
        mode := 1;
        ModeChange := True;
      end else if (Mode < 2) and ((ws[i] = '@') and (PosEx('@', ws, i + 1) = 0)) then
      begin
        mode := 2;
        ModeChange := True;
      end;
    end;
    if not ModeChange then
    begin
      case Mode of
        0: Username := Username + ws[i];
        1: Password := Password + ws[i];
        2: Database := Database + ws[i];
      end;
    end;
  end;
  Result := (Password <> '') or (Database <> '') or (ConnectAs <> '');
end;