CrudRepository 中的自定义 SQL 查询

Question

我正在尝试在扩展 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();}班级是：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 classpublic 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;    }我对如何添加像这样的查询感到困惑：select u_type,count(u_type) from u_user_click_data group by u_type如何更改投影以及其他必要的更改是什么？

Answer 1

您可以将 DAO 更改为以下内容，这应该可以工作。

public interface UserRequestResponseRepository extends CrudRepository<UserRequestResponse, Integer> {

public static final String FIND_QUERY = 

"select new com.abc.datacollection.entity.UserRequestResponse(user.u_httpstatus ,user.u_queryparam, COUNT(user.u_type)) from UserRequestResponse user GROUP BY user.u_type";

@Query(value = FIND_QUERY)

//public List<UserProjection> getAllRequestResponseRecords();

 List<UserProjection> findAllProjectedBy();

}

确保 Bean 类构造函数应该具有传递参数。