案例-修改-修改数据

 

package com.itheima.mapper;

import com.itheima.pojo.Brand;
import org.apache.ibatis.annotations.*;

import java.util.List;

public interface BrandMapper {
    /*
    * 查询所有
    * */
    @Select("select * from tb_brand")
    @ResultMap("brandResultMap")
    List<Brand> selectAll();

    /*
    * 添加
    * */
    @Insert("insert into tb_brand values (null,#{brandName},#{companyName},#{ordered},#{description},#{status})")
    void add(Brand brand);

    /*
     * 根据Id查询
     * */
    @Select("select * from tb_brand where id=#{id}")
    @ResultMap("brandResultMap")
    Brand selectById(int id);

    /*
    * 根据Id修改
    * */
    @Update("update tb_brand set brand_name = #{brandName},company_name = #{companyName},ordered = #{ordered},description = #{description},status = #{status} where id = #{id}")
    void update(Brand brand);

   
}

package com.itheima.service;

import com.itheima.mapper.BrandMapper;
import com.itheima.pojo.Brand;
import com.itheima.util.SqlSessionFactoryUtils;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;

import java.util.List;

public class BrandService {
        //1. 使用工具类获util取到getSqlSessionFactory
        SqlSessionFactory factory = SqlSessionFactoryUtils.getSqlSessionFactory();
    /*
    * 查询所有
    * */
    public List<Brand> selectAll(){
        // 调用BrandMapper.selectAll()

        //2. 获取SqlSession
        SqlSession sqlSession = factory.openSession();

        //3. 获取BrandMapper
        BrandMapper mapper = sqlSession.getMapper(BrandMapper.class);

        //4. 调用方法selectAll()
        List<Brand> brands=mapper.selectAll();

        //返回brand集合，释放资源
        sqlSession.close();
        return brands;
    }

    /*
    * 添加
    * */
    public void add(Brand brand){
        //2. 获取SqlSession
        SqlSession sqlSession = factory.openSession();

        //3. 获取BrandMapper
        BrandMapper mapper = sqlSession.getMapper(BrandMapper.class);

        //调用方法
        mapper.add(brand);

        //提交事务
        sqlSession.commit();

        //释放资源
        sqlSession.close();
    }

    /*
     * 根据Id查询
     * */
    public Brand selectById(int id){

        //2. 获取SqlSession
        SqlSession sqlSession = factory.openSession();

        //3. 获取BrandMapper
        BrandMapper mapper = sqlSession.getMapper(BrandMapper.class);

        //4. 调用方法selectById()
        Brand brand = mapper.selectById(id);

        //返回brand，释放资源
        sqlSession.close();
        return brand;
    }

    /*
     * 修改
     * */
    public void update(Brand brand){
        //2. 获取SqlSession
        SqlSession sqlSession = factory.openSession();

        //3. 获取BrandMapper
        BrandMapper mapper = sqlSession.getMapper(BrandMapper.class);

        //调用方法
        mapper.update(brand);

        //提交事务
        sqlSession.commit();

        //释放资源
        sqlSession.close();
    }

    
}

package com.itheima.web;

import com.itheima.pojo.Brand;
import com.itheima.service.BrandService;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@WebServlet("/updateServlet")
public class UpdateServlet extends HttpServlet {
    private BrandService service=new BrandService();

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        //处理POST请求的乱码问题
        request.setCharacterEncoding("utf-8");

        //1. 接受表单提交的数据，封装为一个Brand对象
        String id = request.getParameter("id");
        String brandName = request.getParameter("brandName");
        String companyName = request.getParameter("companyName");
        String ordered = request.getParameter("ordered");
        String description = request.getParameter("description");
        String status = request.getParameter("status");

        //2. 封装为一个Brand对象
        Brand brand = new Brand();
        brand.setId(Integer.parseInt(id));
        brand.setBrandName(brandName);
        brand.setCompanyName(companyName);
        brand.setOrdered(Integer.parseInt(ordered));
        brand.setDescription(description);
        brand.setStatus(Integer.parseInt(status));

        //2.调用servlet 完成修改
        service.update(brand);

        //3.转发到查询所有Select
        request.getRequestDispatcher("selectAllServlet").forward(request,response);


    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doGet(request, response);
    }

}

<%--
  Created by IntelliJ IDEA.
  User: admin
  Date: 2023/6/30
  Time: 13:25
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <title>修改品牌</title>
</head>
<body>
<h3>修改品牌</h3>
<form action="/brand-demo/updateServlet" method="post">

    <%-- 隐藏域，用来提交ID --%>
    <input type="hidden" name="id" value="${brand.id}">

    品牌名称：<input name="brandName" value="${brand.brandName}"><br>
    企业名称：<input name="companyName" value="${brand.companyName}"><br>
    排序：<input name="ordered"  value="${brand.ordered}"><br>
    描述信息：<textarea rows="5" cols="20" name="description">${brand.description}</textarea><br>
    状态：
    <c:if test="${brand.status == 0}">
        <input type="radio" name="status" value="0" checked>禁用
        <input type="radio" name="status" value="1">启用<br>
    </c:if>

    <c:if test="${brand.status == 1}">
        <input type="radio" name="status" value="0">禁用
        <input type="radio" name="status" value="1" checked>启用<br>
    </c:if>

    <input type="submit" value="提交">
</form>
</body>
</html>