1:pom

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><groupId>org.example</groupId><artifactId>item-center</artifactId><version>1.0-SNAPSHOT</version><packaging>jar</packaging><name>item-center</name><parent><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-parent</artifactId><version>2.2.7.RELEASE</version></parent><properties><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding><start-class>org.example.AppMain</start-class><java.version>1.8</java.version><lombok.version>1.14.8</lombok.version><log4jdbc.log4j2.version>1.16</log4jdbc.log4j2.version><rest.assured.version>2.3.3</rest.assured.version></properties><dependencies><!--SpringBoot启动依赖--><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope></dependency><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>4.13.2</version><scope>test</scope></dependency><!--集成mysql数据库--><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>8.0.26</version></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-jdbc</artifactId><version>2.6.1</version></dependency><!--spring boot集成mybatis的依赖--><dependency><groupId>org.mybatis.spring.boot</groupId><artifactId>mybatis-spring-boot-starter</artifactId><version>2.1.0</version></dependency><dependency><groupId>com.alibaba</groupId><artifactId>druid</artifactId><version>1.1.23</version></dependency><!-- fastjson --><dependency><groupId>com.alibaba</groupId><artifactId>fastjson</artifactId><version>2.0.23</version></dependency></dependencies></project>

2:yml配置

spring:profiles:active: devspring:application:name: item-centerdatasource:url: jdbc:mysql://127.0.0.1:3306/item-centerusername: rootpassword: roottype: com.alibaba.druid.pool.DruidDataSourcemybatis:mapper-locations: classpath:mybatis-mapper/*.xml

3：sql

CREATE TABLE `item-center`.`t_item`  (`id` bigint(11) UNSIGNED NOT NULL AUTO_INCREMENT COMMENT 'id',`name` varchar(50) NULL COMMENT '名称',`price` bigint(11) NULL COMMENT '价格',PRIMARY KEY (`id`)
) ENGINE = InnoDB CHARACTER SET = utf8mb4 COMMENT = '商品';

4：entity

package org.example.entity;import java.io.Serializable;public class ItemDO implements Serializable {private long id;private String name;private long price;}

5:mapper.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapperPUBLIC "-//mybatis.org//DTD Mapper 3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="org.example.mapper.ItemMapper"><select id="listAll" resultType="org.example.entity.ItemDO">select id,name,price from t_item</select><select id="get" resultType="org.example.entity.ItemDO">select id,name,price from t_item where  id=#{id}</select><insert id="insert" useGeneratedKeys="true" keyProperty="id">insert into t_item(name,price)values(#{name},#{price})</insert><update id="update">update t_item setname=#{name},price=#{price}where id=#{id}</update>
</mapper>

6:mapper.class

package org.example.mapper;import org.apache.ibatis.annotations.Mapper;
import org.example.entity.ItemDO;import java.util.List;@Mapper
public interface ItemMapper {public int insert(ItemDO itemDO);public int update(ItemDO itemDO);public int get(long id);public List<ItemDO> listAll();
}

7:test

package org.example;import com.alibaba.fastjson.JSON;
import org.example.entity.ItemDO;
import org.example.mapper.ItemMapper;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;import java.util.List;
import java.util.Random;
import java.util.UUID;@RunWith(SpringRunner.class)
@SpringBootTest(classes = {AppMain.class})
public class ItemTest {@Autowiredprivate ItemMapper itemMapper;@Testpublic void itemAllTest(){ItemDO itemDO = new ItemDO();itemDO.setName("名称"+UUID.randomUUID().toString());itemDO.setPrice(new Random().nextInt(1000));itemMapper.insert(itemDO);System.out.println(JSON.toJSON(itemDO));itemDO.setName("改过后的——>"+itemDO.getName());itemMapper.update(itemDO);List list = itemMapper.listAll();System.out.println(JSON.toJSONString(list));}
}