sql group by子句错误

这就是错误所在

Msg 8120，16级，状态1，更新后的程序，第10行
列“TopicsComplete.TopicCreationDate”在选择列表中无效，因为它未包含在聚合函数或GROUP BY子句中

这是在添加这两行之后，我需要计算一个单独的表行（行的数量不是

topicid

的数量），并在结果中包含任何想法？谢谢

,COUNT(DISTINCT MC.topicid) AS NewMessagesCount

LEFT OUTER JOIN Messages AS MC ON MC.TopicId = T.TopicId AND MC.userid = @id

@id int = null
,@UserGroupId int = null
AS
SELECT
*
FROM
(SELECT
ROW_NUMBER()
        OVER ( ORDER BY TopicOrder desc
                  , CASE WHEN M.MessageCreationDate > T.TopicCreationDate 
                        THEN M.MessageCreationDate
                        ELSE T.TopicCreationDate
                    END desc )
    AS RowNumber,
T.TopicId, T.TopicTitle, T.TopicShortName, T.TopicDescription, T.TopicCreationDate, T.TopicViews, T.TopicReplies, T.UserId, T.TopicTags, T.TopicIsClose, T.TopicOrder, T.LastMessageId, T.UserName, M.MessageCreationDate, T.ReadAccessGroupId, T.PostAccessGroupId, U.UserGroupId, U.UserPhoto, T.UserFullName ,M.UserId AS MessageUserId ,MU.UserName AS MessageUserName
,COUNT(DISTINCT MC.topicid) AS NewMessagesCount

FROM            TopicsComplete AS T  
                 LEFT OUTER JOIN Messages AS M ON M.TopicId = T.TopicId AND M.MessageId = T.LastMessageId AND M.Active = 1  
                 LEFT OUTER JOIN Messages AS MC ON MC.TopicId = T.TopicId AND MC.userid = @id
                 INNER JOIN Users AS U ON U.UserId = T.UserId
LEFT JOIN Users MU ON MU.UserId = M.UserId

WHERE   EXISTS
(SELECT  * FROM    TopicsComplete
                   LEFT OUTER JOIN Messages AS M ON M.TopicId = T.TopicId AND M.MessageId = T.LastMessageId AND M.Active = 1 INNER JOIN
                   topicfollows AS TF ON T.TopicId != TF.topicid INNER JOIN
                   Users AS U ON U.UserId = T.UserId LEFT OUTER JOIN
                   Users AS MU ON MU.UserId = M.UserId
                   WHERE        (T.UserId = @id)

UNION SELECT  * FROM    TopicsComplete
                        LEFT OUTER JOIN Messages AS M ON M.TopicId = T.TopicId AND M.MessageId = T.LastMessageId AND M.Active = 1 INNER JOIN
                        topicfollows AS TF ON T.TopicId = TF.topicid INNER JOIN
                        Users AS U ON U.UserId = T.UserId LEFT JOIN 
                        Users MU ON MU.UserId = M.UserId
                        WHERE        (TF.userid = @id)
      )
) T

---

您需要在

GROUP BY

子句中包含聚合中未包含的任何列（max、min、count、sum等）。

当您在

select

中具有聚合函数时，SQL Server相当合理地假设您要进行聚合。所有不在聚合函数中的列都应该在

group by

子句中

在本例中，在

select

表达式中将

COUNT（DISTINCT MC.topicid）作为newmessagescont

。所有其他列都应位于

分组依据中

。没有

分组依据

，但您仍然会收到错误，因为应该有一个