Question

我已经在java中为这个数据库实现了轮询，并读取驻留在outgoingqueue中的所有传入数据。现在我在更新轮询行时遇到问题，就像我只是在行中更改了一些值，所以

我的问题是：

1.如何循环此表中的行，使其值为ACTION = 804且具有最高的SEQ值。

2.如何通过更改KEYINFO1＆amp;中的值来更新行KEYINFO2如下表所示。

http://imageshack.us/photo/my-images/24/updatinganamolies.png/

enter image description here

这是执行轮询和检查新传入消息的代码

    public void run() { // run method calls the fullpoll() 
    int seqId = 0;
    while(true) {
        List<KamMessage> list = null;
        try {
            list = fullPoll(seqId);
            if (!list.isEmpty()) {
                seqId = list.get(0).getSequence();
                incomingQueue.addAll(list);
                this.outgoingQueue = incomingQueue;
                System.out.println("waiting 3 seconds");
                System.out.println("new incoming message");
                Thread.sleep(3000);
                MessageProcessor processor = new MessageProcessor() {

                    @Override
                    public void run() {
                        generate(dbConnection);

                    }
                };


            }
        } catch (Exception e1) {
            e1.printStackTrace();
        }


       }
     }

    public List<KamMessage> fullPoll(int lastSeq) throws Exception {
    Statement st = dbConnection.createStatement();
    ResultSet rs = st.executeQuery("select * from msg_new_to_bde where ACTION =  804 and 
            SEQ >" + lastSeq + "order by SEQ DESC");  
    List<KamMessage> pojoCol = new ArrayList<KamMessage>();
    try {


        while (rs.next()) {
            KpiMessage filedClass = convertRecordsetToPojo(rs);
            pojoCol.add(filedClass);
        }

        for (KpiMessage pojoClass : pojoCol) {
            System.out.print(" " + pojoClass.getSequence());
            System.out.print(" " + pojoClass.getTableName());
            System.out.print(" " + pojoClass.getAction());
            System.out.print(" " + pojoClass.getKeyInfo1());
            System.out.print(" " + pojoClass.getKeyInfo2());
            System.out.println(" " + pojoClass.getEntryTime());
        }


    } finally  {
        rs.close();
        st.close();
        // TODO: handle exception
    }

所以这是我用于生成行的示例代码，但是如何通过使条件具有最高的SEQ和ACTION值= 804来更新此行

    public void generate()
    {
        KpiMsg804 upd= createKpiMsg804();
        while(true){
            try {
                st = conn.createStatement();
                System.out.println("Updating Values");
        String query = "insert into   
                        msg_new_to_bde(tablename,action,keyinfo1,keyinfo2) values(?, ?, ?, ?)";

                pstmt = conn.prepareStatement(query); // create a statement
                pstmt.setString(1,upd.getTableName());
                pstmt.setInt(2,upd.getAction()); // set value of action
                pstmt.setString(3,upd.getKeyInfo1()); // set key-info value1
                pstmt.setString(4,upd.getKeyInfo2()); // set key-info value2
                int rows = pstmt.executeUpdate();
                System.out.println("Number of Rows Created " +rows);
                // execute insert statement
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        public KpiMsg804 createKpiMsg804()
  {
 KpiMsg804 msg= new KpiMsg804();
     msg.setKeyInfo1("ENTITYKEY2");
     msg.setKeyInfo2("STATUSKEY2");
 return msg;
    }

如何通过将ENTITYKEY和STATUSKEY更改为ENTITYKEY1和STATUSKEY1

来更新序列中表中的两个值来更新

我必须使用一个逻辑，以便我的方法应该查找具有最高序列号和相应ACTIONKEY的行，最后它使用不同的值更新（更改值）行。

P.S：“请求：请给出给予否定分数的理由（大拇指向下）。这样我就能清楚地解释我的问题”

如何在循环中轮询新传入数据后更新表中行的值

0 个答案: