SpringBoot MyBatis连接数据库 查询数据(注解方式)

创建项目时选择依赖

配置数据库连接

在resources中的 application.properties 配置文件进行连接的配置

#驱动名称
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

#连接地址
spring.datasource.url=jdbc:mysql://10.20.22.11:26954/canteen

#数据库用户名
spring.datasource.data-username=abc

#数据库密码
spring.datasource.data-password=123456

实体类封装

属性必须和数据表中的一致

@Data //自动生成 set get 和构造方法
public class Traffic {
   
    
        private   Integer id;
         private  String category;

        private  Integer today;

        private LocalDate into_date;
        
}

查询数据接口

@Mapper //添加这个注解自动生成实现类
public interface TrafficMapper {
   

    @Select("SELECT * FROM number") //查询这个表的所有数据
    public List<Traffic>  getTraffice();

}

通过接口返回数据

@RestController
public class TrafficController {
   

    @Autowired
    private TrafficMapper trafficMapper;



    @GetMapping("/getTraffic")
    public Result getTraffic()
    {
   
        List<Traffic> data =trafficMapper.getTraffic();
        return  Result.success("获取成功",data);
    }



}

{
   "code":200,"meg":"获取成功",
"data":[{
   "id":1000,"category":"一楼","today":2418,"into_date":"2023-12-03"},
{
   "id":1001,"category":"二楼","today":4871,"into_date":"2023-12-03"},
{
   "id":1002,"category":"三楼","today":5471,"into_date":"2023-12-03"}]}