我的表结构如下:
@Entity(tableName = "userFitnessDailyRecords")
public class UserFitnessDailyRecords {
@NonNull
@PrimaryKey
private Date forDay;
private int stepCount;
}
我编写的用于获取总和和平均值的查询语句如下:
@Dao
public interface UserFitnessDailyRecordsDao {
@Query("SELECT SUM(stepCount), AVG(stepCount) FROM userFitnessDailyRecords where forDay BETWEEN :startDay AND :endDay ORDER BY forDay ASC")
UserFitnessDailyRecords getUserFitnessSumAndAverageForLastThirtyDays(Date startDay, Date endDay);
@Query("DELETE FROM userFitnessDailyRecords")
void deleteUserFitnessDailyRecord();
}
在编译时,我遇到了一个错误:由于列中不包含sum和average字段,无法返回值。在这种情况下如何返回sum和average?