使用derby、netbeans和jsp将两列中的值相加并存储到第三列？

CREATE TABLE myTable (
    column1 INT,
    column2 INT,
    column3 INT
);

<%
    // 导入必要的Java类
    <%@ page import="java.sql.*" %>

    // 定义数据库连接信息
    String url = "jdbc:derby://localhost:1527/myDB";
    String username = "username";
    String password = "password";

    // 建立数据库连接
    Connection conn = DriverManager.getConnection(url, username, password);

    // 执行查询操作
    Statement stmt = conn.createStatement();
    ResultSet rs = stmt.executeQuery("SELECT column1, column2 FROM myTable");

    // 处理查询结果
    while (rs.next()) {
        int column1 = rs.getInt("column1");
        int column2 = rs.getInt("column2");
        int column3 = column1 + column2;

        // 更新第三列的值
        stmt.executeUpdate("UPDATE myTable SET column3 = " + column3 + " WHERE column1 = " + column1 + " AND column2 = " + column2);
    }

    // 关闭数据库连接
    rs.close();
    stmt.close();
    conn.close();
%>