SQL更新語句與where子句中的子查詢相同的表

Question

我目前是一名學生，我正試圖解決SQL的一個小問題。我想根據來自同一個表的過濾結果在表上執行更新語句。 Here is the table I have:

這是查詢我到現在：

UPDATE ComplexityLessons 
SET ACADEMYRATIO = '0,896' 
WHERE (
    SELECT c.START, c.DATE, c.ACTIVITY, c.ACADEMY 
from ComplexityLessons c 
join (
    SELECT b.ACTIVITY, b.START, b.DATE 
    FROM ComplexityLessons b 
) as b 
on c.ACTIVITY = b.ACTIVITY and c.DATE = b.DATE and c.START = b.START 
having COUNT(DISTINCT ACADEMY) = 2) 

所以，總結我想更新列「ActivityRatio」僅在2所院校在同一時間進行同樣的活動。當我僅使用子查詢時，我得到了同時執行相同活動的院校，但我無法弄清楚更新聲明。 預先感謝您的幫助！

Answer 1

UPDATE ComplexityLessons SET ACADEMYRATIO = '0,896' 
WHERE (SELECT c.START, c.DATE, c.ACTIVITY, c.ACADEMY 
     from ComplexityLessons c 
join (SELECT b.ACTIVITY, b.START, b.DATE 
     FROM ComplexityLessons b) as b 
on c.ACTIVITY = b.ACTIVITY and c.DATE = b.DATE and c.START = b.START 
having COUNT(DISTINCT ACADEMY) = 2) 

在哪裏應該有條件和子查詢應該返回ID。 例如

UPDATE ComplexityLessons SET ACADEMYRATIO = '0,896' 
WHERE <id> in (SELECT <id> from ComplexityLessons c 
join (SELECT b.ACTIVITY, b.START, b.DATE 
     FROM ComplexityLessons b) as b 
on c.ACTIVITY = b.ACTIVITY and c.DATE = b.DATE and c.START = b.START 
having COUNT(DISTINCT ACADEMY) = 2) 

的應該是表之間的foriegn鍵。