Exception: No primary keys?

pgsql-jdbc

    A simplest test failed when I use postgresql and pgsql-jdbc driver which were build from postgresql7.3b5 source
code.
    The test code is:
..
     14         try{
     15             Class.forName(strDrv);
     16             conn = DriverManager.getConnection(strUrl, "postgl", "");
     17             stmt = conn.createStatement();
     18             rs = stmt.executeQuery(strSql);
     19             while (rs.next())
     20             {
     21                 System.out.println(rs.getString(1));
     22             }
     23             //rs.beforeFirst();
     24             while (rs.previous())
     25             {
     26                 System.out.println(rs.getString(1));
     27             }
     28             rs.moveToInsertRow();
     29             rs.updateInt("a", 100);
     30             rs.insertRow();
     31         } catch(Exception e){
     32             System.out.println(e.toString());
     33         }

       The table "test" has only two columns(a int, b varchar) and no primary keys.
    The error message is: No primary keys.
    It's all right with line 28,29 and 30 commented out.
    It will also succedd when the table "test" has a primary key.
    Can you tell me why?
    My environment is:
    redhat 7.3
    j2sdk1.4.1_01
    ant1.5.1

    Thanks and regards,
　　　　　　　　


　　　　　　　　Han
　　　　　　　　zhouhanok@vip.sina.com
　　　　　　　　　　2002-12-02