查詢另一個查詢的結果

Question

我希望再次查詢括號中的查詢結果。 我在堆棧中引用了幾篇文章，並提出了以下查詢。 但是不知何故，第二個查詢（括號外的那個）不起作用。 錯誤表明第二個“組”附近語法不正確。 有人可以幫忙嗎？

select CourseID, count(CourseID)
from
    (select CustomisationID, CourseID , Count(CourseID)
     from tblFilter
     where CustomisationID in (43, 51) 
     group by CourseID, CustomisationID) 
group by CourseID

Answer 1

嘗試這個

select M.CourseID, count(M.CourseID) from
(
   select CustomisationID, CourseID , Count(CourseID) AS Cnt from tblFilter where CustomisationID in (43,51) 
    group by CourseID, CustomisationID
)M 
group by M.CourseID

Answer 2

您必須為子查詢設置別名。 嘗試這樣的事情：

select CourseID, count(CourseID) 
from
(
    select CustomisationID, CourseID , Count(CourseID) AS Cnt
    from tblFilter 
    where CustomisationID in (43,51) 
    group by CourseID, CustomisationID
) AS TMP
group by CourseID