public  List<Object>getColumnValues(String table,Column column, QUERY_TYPE modality) throws SQLException{
        LinkedList<Object> valueSet = new LinkedList<Object>();
        String query="";
        if(modality.equals(QUERY_TYPE.DISTINCT)){
            query="SELECT DISTINCT"+column.getColumnName()+"FROM"+table;}
        else{
            query="SELECT"+column.getColumnName()+"FROM"+table+"ORDER BY"+column.getColumnName();}

        Statement statement = DbAccess.getConnection().createStatement();//connessione al Database
        ResultSet rs = statement.executeQuery(query);//eseguo la query

        while(rs.next()){//ciclo sulle tuple
            if(column.isNumber()){
                valueSet.add(rs.getFloat(1));
                }
            else{
                valueSet.add(rs.getString(1));}
            }
        return valueSet;

    }