package servlet;

import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class Servlet extends HttpServlet {

  /**
   * Constructor of the object.
   */
  public Servlet() {
    super();
  }

  /**
   * Destruction of the servlet. <br>
   */
  public void destroy() {
    super.destroy(); // Just puts "destroy" string in log
    // Put your code here
  }

 
  public void doGet(HttpServletRequest request, HttpServletResponse response)
      throws ServletException, IOException {

    response.setContentType("text/html;charset=utf-8");
      request.setCharacterEncoding("utf-8");
    String useName=request.getParameter("userName");
   int  id= Integer.parseInt(request.getParameter("id"));
      try {
      Class.forName("com.mysql.jdbc.Driver");
        Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/school", "root", "ok");
        Statement sm = con.createStatement();
        String sql="insert into grade  values ('"+id+"','"+useName+"')"; 
        if (sm.executeUpdate(sql)>0) {
        System.out.println("新增成功！！");
      }
    } catch (ClassNotFoundException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    } catch (SQLException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }
      
      
  }

   
  public void doPost(HttpServletRequest request, HttpServletResponse response)
      throws ServletException, IOException {

    response.setContentType("text/html");
     doGet(request, response);
  }

   
}
statement.execute("update 表名 set user_id='"+参数+"' where id='"+Id+"'");这种格式