Simpatic question on datatable...

Hi guys,
i've a great problem with JSF application and i'm not able to go on.
I've defined a datatable and it works fine.
I have an edit link that clicked allow user to edit fields in another
page.
I want to know if

1) Does exists a method for showing datatable giving immediately
possibility to user to modify fields, whitout press edit botton?
Can you say me how can i do it?

2) i'm trying to working this save method, to save an edited row but it
performs navigation but not update values

public String saveUser(){
     try{
     UsersTable table=new UsersTable();
     table.getUserItem();
            DataSource dataSource=Singleton.getInstance().getDataSource();
            Connection conn=dataSource.getConnection();
            if (conn != null) {
                PreparedStatement pst = null;
                pst = conn.prepareStatement("UPDATE utente set
username="+userItem.login+"password="+userItem.password+"nomegruppo="+userItem.teamname+"tipo="+userItem.role+"nome="+userItem.firstName+"cognome="+userItem.lastName+"citta="+userItem.city+"datanascita="+userItem.date+"indirizzo="+userItem.address+"professione="+userItem.profession+"email="+userItem.email);
                pst.executeUpdate();
                pst.close();
                conn.close();

            }
     }
        catch(Exception e){};

    return "ok";
    }

Can you help me?
I'm bit confused...