SpringDateJpa 查询返回自定义对象，非po对象。

1.使用原生sql查询。自定义接受类为对象,(貌似不支持对象属性)。

@Repository
public interface UserRepository extends JpaRepository<User,String> {

    @Query(value = "select * from User",nativeQuery = true)
    List<IUserDTO> selectIUserDTO();

}

package com.example.test1.dto;

public interface IUserDTO {
    String getId();
    String getName();
    String getAge();
}

参考

https://my.oschina.net/xiwanglr/blog/3067932

https://blog.youkuaiyun.com/kuangniaokuang/article/details/105249490

https://www.baeldung.com/spring-data-jpa-projections

2.hql。

    @Query("select new com.example.test1.dto.UserDTO(u.id,u.age,u.name) from User u where u.id=1")
    UserDTO selectUserDTO();

package com.example.test1.dto;

public class UserDTO {
    private String id;
    private String age;
    private String name;

    @Override
    public String toString() {
        return "UserDTO{" +
                "id='" + id + '\'' +
                ", age='" + age + '\'' +
                ", name='" + name + '\'' +
                '}';
    }

    public UserDTO(String id, String age, String name) {
        this.id = id;
        this.age = age;
        this.name = name;
    }

    public UserDTO() {
    }

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getAge() {
        return age;
    }

    public void setAge(String age) {
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}