项目第一章第1节--Mybaits打通Mysql数据库

第一步：在application.properties中添加数据库配置

server.port=8081
#==============================数据库相关配置========================================
spring.datasource.driver-class-name =com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://127.0.0.1:3306/online_yspan?useUnicode=true&characterEncoding=utf-8&useSSL=false
spring.datasource.username=root
spring.datasource.password=root

#使用阿里巴巴druid数据源，默认使用自带的
#spring.datasource.type =com.alibaba.druid.pool.DruidDataSource
#开启控制台打印sql
mybatis.configuration.log-impl=org.apache.ibatis.logging.stdout.StdOutImpl

# mybatis 下划线转驼峰配置,两者都可以
#mybatis.configuration.mapUnderscoreToCamelCase=true
mybatis.configuration.map-underscore-to-camel-case=true

#配置扫描
mybatis.mapper-locations=classpath:mapper/*.xml
#配置xml的结果别名
mybatis.type-aliases-package=work.yspan.online.domain

第二步：创建VideoMapper.xml 以及mapper下的VideoMapper接口

VideoMapper.xml

DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="work.yspan.online.mapper.VideoMapper">
    <select id="listVideo" resultType="Video">
        select * from video
    select>
mapper>

第三步：创建service下的VideoService和VideoServiceImpl
VideoService

public interface VideoService {
    List<Video> listVideo();
}

VideoServiceImpl

@Service
public class VideoServiceImpl implements VideoService {

    @Autowired
    private VideoMapper videoMapper;

    @Override
    public List<Video> listVideo() {
        return videoMapper.listVideo();
    }
}

第四步：创建controller下的VideoController
VideoController

@RestController
@RequestMapping("video")
public class VideoController {
    @Autowired
    private VideoService videoService;
    @RequestMapping("list")
    public Object listVideo(){
        return videoService.listVideo();
    }
}

第五步：启动类添加mapper扫描

效果截图：