@Entity
public class Country {
    //實體類參考本人部落格地址：https://blog.csdn.net/yl_hahha/article/details/80208161
    @Id
    @GeneratedValue
    private long id;
    private String countryname;
    private String countrycode;
    public long getId() {
        return id;
    }
    public void setId(long id) {
        this
 
.id = id;
    }
    public String getCountryname() {
        return countryname;
    }
    public void setCountryname(String countryname) {
        this.countryname = countryname;
    }
    public String getCountrycode() {
        return countrycode;
    }
    public void setCountrycode(String countrycode) {
        this
 
.countrycode = countrycode;
    }
    @Override
    public String toString() {
        return "Country [id=" + id + ", countryname=" + countryname + ", countrycode=" + countrycode + "]";
    }
}

public interface CountryDao  extends JpaRepository<Country,Long>{

}

@SpringBootApplication
public
 
 class DemoApplication {
    /**
     * Failed to determine a suitable driver class
     * 說明你沒有配置資料來源 或者資原始檔不認識yum檔案
     * @param args
     */
    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }
}
[專案地址](https://github.com/ylha/springboot-web1)