springboot jpa 实现返回结果自定义查询

@Data
public class NameOnlyDto   implements Serializable {
    private  String  firstName;
    private  String  lastName;
    private  String  sex ;
}

@Repository
public class CustomEntity {
    // 实体管理器EntityManager是负责管理Entity的对象。对Entity的操作包括添加、删除、修改和查询，都是通过实体管理器来实现的。
    @PersistenceContext
    private EntityManager entityManager;
 
    //EntityManagerFactory
 
    @Transactional
    public List<NameOnlyDto> listNameOnlyDto(){
        String sql = "select p.last_name lastName, p.first_name firstName from PERSON p";
        // hibernate 5.2 之前
        // SQLQuery sqlQuery = entityManager.createNativeQuery(sql).unwrap(NativeQueryImpl.class);
        // hibernate 5.2 之后的 写法
 
        // unwrap 让JPA的Query返回Map对象 javax.persistence.Query.unwrap
        // hibernate 或jpa 中使用 AliasToBeanResultTransformer 自定义类型转换ResultTransformer 下划线转驼峰
        SQLQuery sqlQuery = entityManager.createNativeQuery(sql).unwrap(NativeQueryImpl.class);
        /*Query query =
                sqlQuery.setResultTransformer(Transformers.aliasToBean(NameOnlyDto.class));
        List<NameOnlyDto> list = query.getResultList();//.list();*/
 
        Query query =
                sqlQuery.setResultTransformer(Transformers.aliasToBean(NameOnlyDto.class));
 
        List<NameOnlyDto>  list =query.getResultList();
        entityManager.clear();
        return list;
    }
}

public class NameOnlyDtoT implements Serializable {
    private  String  firstName;
    private  String  lastName;
    // private  String  address;
    private  String  sex;
    //构造函数 特殊注意 这里返回几个字段就要有几个字段的构造参数 感觉不太合适的地方
    public NameOnlyDtoT(String firstName, String lastName) {
        this.firstName = firstName;
        this.lastName = lastName;
    }
   /* public NameOnlyDtoT(String firstName, String lastName, String sex) {
        this.firstName = firstName;
        this.lastName = lastName;
        this.sex = sex;
    }*/
}

// 切记不能使用@query.如果使用@query 个人感觉和上面那种方法是一样的逻辑
List<T> findByLastName(String lastname,Class<T> type);
        使用（这里注意的是NameOnlyDtoT 中字段能赋值的只能是person中 含有的字段。这是个人觉得鸡肋的存在）
    public  List<NameOnlyDtoT>  testNameOnlyDtoTS(){
        List<NameOnlyDtoT>  nameOnlyDtoTS= personRepository.findByLastName("哈哈", NameOnlyDtoT.class);
      return nameOnlyDtoTS;
}

        <!-- web依赖 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!--  lombok依赖 -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.8</version>
        </dependency>
        <!-- jpa依赖 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <!-- mysql依赖 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>

server:
  port: 13333
spring:
  datasource:
    url: jdbc:mysql://localhost:3306/test?characterEncoding=UTF-8&autoReconnect=true&serverTimezone=Asia/Shanghai&zeroDateTimeBehavior=convertToNull
    username: root
    password: 12345678
    driver-class-name: com.mysql.jdbc.Driver
  jpa:
    show-sql: true
    hibernate:
      ddl-auto: none

package com.lss.jpa.dao;
import com.lss.jpa.entity.dto.UserAddressDto;
import com.lss.jpa.entity.po.User;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.Query;
import java.util.List;
import java.util.Map;
public interface UserDaoRepository extends JpaRepository<User, Integer> {
    @Query(value = "select \"title\" as common, u.id as id, u.name as name, a.id as addressId, a.address as addressName from user u, address a where u.id = a.user_id", nativeQuery = true)
    public List<UserAddressDto> findAllUserAddress();
    @Query(value = "select \"title\" as common, u.id as id, u.name as name, a.id as addressId, a.address as addressName from user u, address a where u.id = a.user_id and u.id=1", nativeQuery = true)
    public UserAddressDto findAllUserAddressById();
    @Query(value = "select \"title\" as common, u.id as id, u.name as name, a.id as addressId, a.address as addressName from user u, address a where u.id = a.user_id and u.id=1", nativeQuery = true)
    public Map<String, Object> findAllUserAddressByMap();
}

package com.lss.jpa.entity.dto;
public interface UserAddressDto {
    Integer getId();
    String getName();
    String getAddressName();
    Integer getAddressId();
    String getCommon();
}

package com.lss.jpa.web;
import com.lss.jpa.dao.UserDaoRepository;
import com.lss.jpa.entity.dto.UserAddressDto;
import com.lss.jpa.entity.po.User;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import java.util.List;
import java.util.Map;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
@RestController
@Slf4j
public class TestController {
    @Autowired
    private UserDaoRepository userDaoRepository;
    @GetMapping("test")
    public String test(){
        List<UserAddressDto> all = userDaoRepository.findAllUserAddress();
        all.stream().forEach(dto -> {
            log.info("result: id:{}, name:{}, addressId:{}, addressName:{}, common:{}", dto.getId(), dto.getName(), dto.getAddressId(), dto.getAddressName(), dto.getCommon());
        });
        UserAddressDto dto = userDaoRepository.findAllUserAddressById();
        log.info("result: id:{}, name:{}, addressId:{}, addressName:{}, common:{}", dto.getId(), dto.getName(), dto.getAddressId(), dto.getAddressName(), dto.getCommon());
        Map<String, Object> map = userDaoRepository.findAllUserAddressByMap();
        log.info("map:{}", map);
        List<User> userList = userDaoRepository.findAll();
        log.info("userList:{}", userList);
        return "ok";
    }
}