【Android開發】& Expected unique result, but count was 2

使用greendao獲取數據，如下query.unque。如果當前的記錄數大於一條，再使用query.unique則會報如題的報錯。

            Query<EntityBuildingPicInfo> query=entityBuildingPicInfoDao.queryBuilder().where(EntityBuildingPicInfoDao.Properties.Buildinginfo_uuid.eq(
                    longID)).build();
            EntityBuildingPicInfo entityBuildingPicInfo=query.unique();