jsp对mysql增删改查

<%@ page import="java.sql.*" %>
<%
    String url = "jdbc:mysql://localhost:3306/mydatabase";
    String username = "user";
    String password = "password";

    Connection conn = null;
    Statement stmt = null;
    ResultSet rs = null;

    try {
        // 1. 建立数据库连接
        Class.forName("com.mysql.jdbc.Driver");
        conn = DriverManager.getConnection(url, username, password);

        // 2. 执行SQL语句
        stmt = conn.createStatement();

        // 查询示例
        rs = stmt.executeQuery("SELECT * FROM mytable");
        while (rs.next()) {
            out.println(rs.getString("columnName"));
        }

        // 插入示例
        stmt.executeUpdate("INSERT INTO mytable (column1, column2) VALUES ('value1', 'value2')");

        // 更新示例
        stmt.executeUpdate("UPDATE mytable SET column1='newValue' WHERE id=1");

        // 删除示例
        stmt.executeUpdate("DELETE FROM mytable WHERE id=2");

    } catch (ClassNotFoundException | SQLException e) {
        e.printStackTrace();
    } finally {
        // 3. 关闭连接
        try {
            if (rs != null) rs.close();
            if (stmt != null) stmt.close();
            if (conn != null) conn.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
%>