也许我找到了解决办法

SELECT SUM(Value) AS energiaSettimanale
        FROM (
            SELECT MAX(Value) as value, WEEKDAY(DataOra) as d
            FROM table
            WHERE WEEK(DATE(DataOra)) = WEEK(NOW())
            AND WEEKDAY(DATE(DataOra)) >= 0
            AND WEEKDAY(DATE(DataOra)) <= 6
            GROUP BY d
        ) AS subquery;

如果我真的理解了你想要什么，这个请求可能就是解决方案（如果我理解正确的话，我就是在指定）

select sum(value) from `table` 
inner join ( 
 select max(DataOra) as maxDataOra 
 from `table` 
 where WEEK(DATE(DataOra))=WEEK(NOW()) 
 group by WEEKDAY(DataOra)  
) 
as tmp on DataOra=tmp.maxDataOra

查找一天中最近日期的技巧是使用dateTime Data上的max（）函数按天数分组。

可以使用inner join执行此操作，如下所示：

select weekNumber, sum(value) from (
  select t.value, week(s.maxDataOra) as weekNumber
  from _table t
  inner join (
    select MAX(DataOra) as maxDataOra
    from _table
    group by DATE(DataOra)
  ) as s on s.maxDataOra = t.DataOra
) as b
group by weekNumber;

点击这里查看：https://dbfiddle.uk/hadzywwh

我需要对当前周的每一天的最后一个值（按日期）求和。
所以，让我们先把工作集限制为当前周的数据-

WHERE `DataOra` >= (CURRENT_DATE - INTERVAL(WEEKDAY(CURRENT_DATE)) DAY) /* first day of current week (Mon - Sun) */
AND `DataOra` < (CURRENT_DATE - INTERVAL(WEEKDAY(CURRENT_DATE)) DAY + INTERVAL 1 WEEK) /* first day of next week (Mon - Sun) */

然后，我们可以使用它来约束用于获取每个DATE（DataOra）的MAX（DataOra）的查询，并联接回原始数据集以获取各个Value s的总和-

SELECT SUM(`Value`) `energiaSettimanale`
FROM `table` `t1`
INNER JOIN (
    SELECT MAX(`DataOra`) AS `maxDataOra`
    FROM `table`
    WHERE `DataOra` >= (CURRENT_DATE - INTERVAL(WEEKDAY(CURRENT_DATE)) DAY) /* first day of current week (Mon - Sun) */
    AND `DataOra` < (CURRENT_DATE - INTERVAL(WEEKDAY(CURRENT_DATE)) DAY + INTERVAL 1 WEEK) /* first day of next week (Mon - Sun) */
    GROUP BY DATE(`DataOra`)
) `t2` ON `t2`.`maxDataOra` = `t1`.`DataOra`;

或者，如果使用MySQL〉= 8.0，则可以使用ROW_NUMBER（）窗口函数-

SELECT SUM(`Value`) `energiaSettimanale`
FROM (
    SELECT `Value`, ROW_NUMBER() OVER (PARTITION BY DATE(`DataOra`) ORDER BY `DataOra` DESC) `rn`
    FROM `table`
    WHERE `DataOra` >= (CURRENT_DATE - INTERVAL(WEEKDAY(CURRENT_DATE)) DAY) /* first day of current week (Mon - Sun) */
    AND `DataOra` < (CURRENT_DATE - INTERVAL(WEEKDAY(CURRENT_DATE)) DAY + INTERVAL 1 WEEK) /* first day of next week (Mon - Sun) */
) `t`
WHERE `rn` = 1;