我试图在扩展CrudRepository的存储库中执行一些SQL查询。我在控制器中有以下代码：

@CrossOrigin(origins = "*")
    @GetMapping(path="/all")
    public @ResponseBody List<UserProjection> getAllRequestResponseRecords() {
        return userRequestResponseRepository.findAllProjectedBy() ;
    }

DAO代码如下：

public interface UserRequestResponseRepository extends CrudRepository<UserRequestResponse, Integer> {
    //public static final String FIND_QUERY = "select user.u_httpstatus ,user.u_queryparam from UserRequestResponse user";
    public static final String FIND_QUERY = 
    "select new com.abc.datacollection.entity.UserRequestResponse(user.u_httpstatus ,user.u_queryparam) from UserRequestResponse user";
    @Query(value = FIND_QUERY)
    //public List<UserProjection> getAllRequestResponseRecords();
     List<UserProjection> findAllProjectedBy();

}

该类是：

import java.sql.Date;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;

@Entity // This tells Hibernate to make a table out of this class
public class UserRequestResponse {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)

    private String u_httpstatus;

    private String u_error_message;

    private String u_queryparam;

    public UserRequestResponse(String u_httpstatus, String u_queryparam) {
        this.u_httpstatus = u_httpstatus;
        this.u_queryparam = u_queryparam;
    }


    public String getU_httpstatus() {
        return u_httpstatus;
    }

    public void setU_httpstatus(String u_httpstatus) {
        this.u_httpstatus = u_httpstatus;
    }

    public String getU_error_message() {
        return u_error_message;
    }

    public void setU_error_message(String u_error_message) {
        this.u_error_message = u_error_message;
    }

    public String getU_queryparam() {
        return u_queryparam;
    }

    public void setU_queryparam(String u_queryparam) {
        this.u_queryparam = u_queryparam;
    }


}

投影为：

public interface UserProjection {
    String getU_httpstatus();
    String getU_queryparam();

}

我对如何添加查询（诸如此类）感到困惑：

select u_type,count(u_type) from u_user_click_data group by u_type

我如何更改投影，还有哪些其他必要的更改？