Question

请告诉我这个查询有什么问题？

with myFriends as (select objectAuthor,memberId,objectSubject,rating,memberSubjectEq4 from tblRating group by objectAuthor,memberId,objectSubject,rating,memberSubjectEq4)
select authorId,subjectId,(
    (
        select memberSubjectEq4*(sum(rating)+1) from myFriends where myFriends.objectAuthor=AAA.authorId and myFriends.objectSubject=AAA.subjectId
    )

) as XF from tblMC AAA group by authorId,subjectId;

当我在MS SQL Server 2014中运行它时，我将收到以下错误：

列'myFriends.memberSubjectEq4'在选择列表中无效因为它不包含在聚合函数或 GROUP BY子句。

Answer 1

使用列执行聚合函数后，必须将其余部分包含在Group By

中

with myFriends as (select objectAuthor,memberId,objectSubject,rating,memberSubjectEq4 from tblRating group by objectAuthor,memberId,objectSubject,rating,memberSubjectEq4)
select authorId,subjectId,(
    (
        select memberSubjectEq4*(sum(rating)+1) from myFriends where myFriends.objectAuthor=AAA.authorId and myFriends.objectSubject=AAA.subjectId
        group by memberSubjectEq4
    )

) as XF from tblMC AAA group by authorId,subjectId;

Answer 2

您可以将计算移动到CTE中，然后将其连接到CTE以获得XF数量。

WITH    myFriends AS 
(   SELECT  objectAuthor,
            objectSubject,
            memberSubjectEq4 * (SUM(rating) + 1) AS XF
    FROM    tblRating
    GROUP BY  objectAuthor,
            objectSubject,
            memberSubjectEq4
)
SELECT  authorId,
        subjectId,
        SUM(myFriends.XF) XF
FROM    tblMC AAA
        LEFT JOIN myFriends ON myFriends.objectAuthor = AAA.authorId
                                AND myFriends.objectSubject = AAA.subjectId
GROUP BY authorId,
        subjectId;

SQL'with'和'group by'子句

2 个答案: