day07 ssm框架数据库操作

最新推荐文章于 2024-10-18 08:34:07 发布

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最新推荐文章于 2024-10-18 08:34:07 发布

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本文链接：https://blog.youkuaiyun.com/ISTUC/article/details/99486686

本文详细介绍了使用MyBatis进行数据库操作的具体步骤，包括如何定义DAO接口、实现Mapper文件、创建Service及Controller层，以及如何在Controller中调用Service方法完成数据库的增删改查操作。

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重启软件可能可以解决404问题 idea 有毒

数据库增删改查

添加数据库方法 dao>Mapper>service>serviceImple>controller

自动创建的标记@Autowired

dao-》IUserDao

public interface IUserDao {
    List<TbUser> findAll();
    void delUser(int id);
    void updateUser(TbUser user);
    TbUser findOne(int id);
    void addUser(TbUser user);
}

mapper->TbUserMapper

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="com.zhongruan.dao.IUserDao" >
    <select id="findAll" resultType="com.zhongruan.bean.TbUser">
        select * from tb_user
    </select>

    <delete id="delUser" parameterType="java.lang.Integer" >
        delete  from tb_user where id =#{id}
    </delete>

    <update id="updateUser" parameterType="com.zhongruan.bean.TbUser">
        update tb_user set username = #{username},password=#{password} where id = #{id};
    </update>

    <select id="findOne" parameterType="java.lang.Integer" resultType="com.zhongruan.bean.TbUser">
        select * from tb_user where id = #{id}
    </select>

    <insert id="addUser" parameterType="com.zhongruan.bean.TbUser">
        insert into tb_user(username,password) value(#{username},#{password})
    </insert>
</mapper>

service>IUserService

public interface IUserService {
    List<TbUser> findAll();
    void delUser(int id);
    void updateUser(TbUser user);
    TbUser findOne(int id);
    void addUser(TbUser user);
}

service>impl>UserServiceImpl

public class UserServiceImpl implements IUserService {

    @Autowired
    private IUserDao userDao;//mapper自动创建

    @Override
    public List<TbUser> findAll() {
        return userDao.findAll();
    }

    @Override
    public void  delUser(int id){
        userDao.delUser(id);
    }


    @Override
    public void updateUser(TbUser user) {
        userDao.updateUser(user);
    }

    @Override
    public TbUser findOne(int id) {
        return userDao.findOne(id);
    }

    @Override
    public void addUser(TbUser user) {
        userDao.addUser(user);
    }
}

controller>UserController


@RequestMapping("user")
@Controller
public class UserController {

    @Autowired
    IUserService userService;

    @RequestMapping("findAll.do")
    public ModelAndView findAll(){
        List<TbUser> users = userService.findAll();
        ModelAndView mv = new ModelAndView();
        mv.addObject("us",users);
        mv.setViewName("allUser");
        return mv;
    }

    @RequestMapping("delete.do")
    public ModelAndView delUser(int id){
        userService.delUser(id);
        return findAll();
    }

    @RequestMapping("toUpdate.do")
    public ModelAndView toUpdate(int id){
        ModelAndView mv = new ModelAndView();
        mv.addObject("userInfo",userService.findOne(id));
        mv.setViewName("updateUser");
        return mv;
    }

    @RequestMapping("update.do")
    public ModelAndView updateUser(TbUser tbUser){
        userService.updateUser(tbUser);
        return findAll();
    }

    @RequestMapping("toAddUser.do")
    public ModelAndView toAddUser(){
        ModelAndView mv = new ModelAndView();
        mv.setViewName("addUser");
        return mv;
    }
    @RequestMapping("save.do")
    public ModelAndView save(HttpServletRequest request){
        TbUser tbUser = new TbUser();
        tbUser.setUsername(request.getParameter("username"));
        tbUser.setPassword(request.getParameter("password"));
        userService.addUser(tbUser);
        return findAll();
    }
}