如何仅使用Java获取forward类型的结果集中的前一行值

Id用户名FirstName姓氏TimeRegistered

戴米思·大卫·史密斯2008-04-02 18:16:22
4.奈杰尔·罗伯茨旅馆2008-05-01 20:11:01 史密斯夫妇比尔·史密斯2008-05-02:43:52

 ResultSet rs = st.getResultSet();
    try {
      while (rs.next()) {
        int id = rs.getInt("Id");
        String userName = rs.getString("UserName");
        String firstName = rs.getString("FirstName");
        String surname = rs.getString("Surname");
       //How to get the previous row value usning resultset of type forward only.
        Timestamp prevtimeReg = rs.getTimestamp("TimeRegistered");

        Timestamp nexttimeReg= rs.getTimestamp("TimeRegistered");

      }
    } finally {
      rs.close();
    }

您使用它的方式如下：

Timestamp prevtimeReg = null;
while (rs.next()) {
    int id = rs.getInt("Id");
    String userName = rs.getString("UserName");
    String firstName = rs.getString("FirstName");
    String surname = rs.getString("Surname");
    Timestamp nexttimeReg= rs.getTimestamp("TimeRegistered");
    //do your operation with previous time stamp
    Timestamp prevtimeReg = nexttimeReg;
 }

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假设第一行没有任何以前的时间戳。然后，当您获得当前行时间戳时，您使用最后一个时间戳执行操作，并使用当前时间戳重置上一个时间戳。

您将其存储在变量中，并在下一次迭代时读取该变量？