SpringBoot 整合mybatis

1.创建一个project

 

 

 2.在pow.xml中导入依赖

<!-- https://mvnrepository.com/artifact/org.mybatis.spring.boot/mybatis-spring-boot-starter -->
<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>1.3.2</version>
</dependency>

注这个依赖是不属于springboot官方底下的，它是自己研发的，提供整合

 

3.创建一个pojo文件夹，并在里面创建一个实体类User

 

package com.yao.pojo;


import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@AllArgsConstructor
@NoArgsConstructor
//以上三个注解需要引入lombok依赖
public class User {

    private int id;
    private String name;
    private String pwd;
}

<dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
</dependency>

4.创建mapper文件夹，并在里面放与mybatis相关的mapper文件

 

 

 继续完善我们的mapper

package com.yao.mapper;

import com.yao.pojo.User;
import org.apache.ibatis.annotations.Mapper;
import org.springframework.stereotype.Repository;

import java.util.List;

@Mapper//表示本类是一个mybatis的mapper类
@Repository//dao层的注解
public interface UserMapper {
    
    List<User> queryUserList();
    
    User queryUserById(int id);
    
    int addUser(User user);
    
    int update(User user);
    
    int delete(User user);
}

5.在resources文件夹下创建mapper文件夹，并在mapper文件夹下创建一个xml，编写xml

5.1

 

 

 

 

 5.2

在mybatis官网--》入门下找到，并粘贴到你的mapper。xml中

 

 

 

 

 

 但是我们这里发现这个UserMapper.xmlspringboot无法识别，而且还需要定义别名等等问题，因此需要在application.properties

中去整个mybatis

5.3在application.properties中整合mybatis

 

 

 继续编写好UserMapper.xml

<?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">
<!--第一步先绑定-->
<mapper namespace="com.yao.mapper.UserMapper">

    <!--
    <cache/>表示开启缓存
    你也可以这样添加缓存：
    <select id="queryUserList" resultType="User" userCache="true">
        select * from user
    </select>
    这样表示这条查询会用一个固定的缓存，第二次查的时候就会从缓存里面去拿-->
    
    
    <select id="queryUserList" resultType="User">
        select * from user
    </select>

    <select id="queryUserById" resultType="Integer">
        select * from user where id = #{id}
    </select>

    <insert id="addUser" parameterType="User">
        insert into user (id,name,pwd) values (#{id},#{name},#{pwd})
    </insert>

    <update id="updateUser" parameterType="User">
        update user set name=#{name},pwd=#{pwd} where id = #{id}
    </update>

    <delete id="deleteUser" parameterType="Integer">
        delete from user where id = #{id}
    </delete>
</mapper>

5.4创建controller

package com.yao.controller;

import com.yao.mapper.UserMapper;
import com.yao.pojo.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
public class UserController {

    @Autowired
    private UserMapper userMapper;

    @GetMapping("/queryUserList")
    public List<User> queryUserList(){
        List<User> userList = userMapper.queryUserList();
        for (User user : userList) {
            System.out.println(user);
        }
        return userList;
    }

    //根据id选择用户
    @GetMapping("/selectUserById")
    public String selectUserById(){
        User user = userMapper.queryUserById(1);
        System.out.println(user);
        return "ok";
    }
    //添加一个用户
    @GetMapping("/addUser")
    public String addUser(){
        userMapper.addUser(new User(10,"阿毛","456789"));
        return "ok";
    }
    //修改一个用户
    @GetMapping("/updateUser")
    public String updateUser(){
        userMapper.updateUser(new User(5,"阿毛","421319"));
        return "ok";
    }
    //根据id删除用户
    @GetMapping("/deleteUser")
    public String deleteUser(){
        userMapper.deleteUser(5);
        return "ok";
    }


}