73-2: Spring MyBatis mapper

1. DB의 아래의 관계에 대하여 설명하시오.

• 일대일 관계 : monogamy
• 일대다 관계 : polygamy
• 다대다 관계 : polyamory

2. 다음과 같이 나오도록 하시오. 다음과 같이 나오도록 하시오.

• /emp/salgrade 접속시
• 이름 월급 월급등급

<!-- code1 -->
				<c:forEach var="empSalgrade" items="${empSalgrades }">
					<tr>
						<td>${empSalgrade.ename }</td>
						<td>${empSalgrade.sal }</td>
						<td>${empSalgrade.grade }</td>
					</tr>
				</c:forEach>

//code2
@Slf4j
@Controller
@RequestMapping("/emp")
public class EmpController {
	@Autowired
	private DeptService deptService;
	@GetMapping("/salgrade")
	public String salgrade(Model model) {
		log.info("salgrade()..");
		model.addAttribute("empSalgrades", empService.getEmpSalgradeVOList());
		return "/emp/salgrade";
	}
}

//code3
public interface EmpService {
	List<EmpSalgradeVO> getEmpSalgradeVOList();
}

//code4
@Slf4j
@Service
public class EmpServiceImpl implements EmpService {
	@Autowired
	private EmpMapper empMapper;
	@Override
	public List<EmpSalgradeVO> getEmpSalgradeVOList() {
		log.info("getEmpSalgradeVOList()..");
		return empMapper.selectEmpSalgradeList();
	};
}

//code5
@Mapper
public interface EmpMapper {
	List<EmpSalgradeVO> selectEmpSalgradeList();
}

<!-- code6 -->
<mapper namespace="edu.sejong.ex.mapper.EmpMapper">
    <select id="selectEmpSalgradeList" resultType="edu.sejong.ex.vo.EmpSalgradeVO">
        <![CDATA[
        	select * from emp, salgrade where sal >= losal and sal <= hisal
        ]]>
    </select>
</mapper>