错误不是一个群组功能

Question

我想只显示前两个建筑物及其相应的平均会话价格。 这就是我现在所拥有的

SELECT BUILDINGLANE,SUM(SESSIONPRICE/COUNT(BUILDINGNO)) 
FROM BUILDING NATURAL JOIN CONFERENCESESSION 
GROUP BY BUILDINGLANE 
WHERE SUM(SESSIONPRICE/COUNT(BUILDINGNO)); 

，但我得到的错误“SQL命令不能正确地结束” 3线，但随后如果我结束第3行以分号，我得到这个新的错误“不一个单组功能“的第1行。林不知道我会出错哪里，我试图寻找这个，但我没有任何运气来解决这个问题。

任何帮助表示赞赏！

Answer 1

您应该使用的Order by代替Where条款

SELECT * 
FROM (SELECT BUILDINGLANE, 
       Sum(intrPrice) AS avgPrice 
     FROM (SELECT BUILDINGLANE, 
         SESSIONPRICE/Count(BUILDINGNO) AS intrPrice 
       FROM BUILDING 
         NATURAL JOIN CONFERENCESESSION 
       GROUP BY BUILDINGLANE, 
          SESSIONPRICE) a 
     GROUP BY BUILDINGLANE 
     ORDER BY avgPrice DESC) b 
WHERE ROWNUM <= 2 

Answer 2

尝试：

select * from(
    SELECT BUILDINGLANE,SUM(SESSIONPRICE)/COUNT(BUILDINGNO) 
    FROM BUILDING NATURAL JOIN CONFERENCESESSION 
    GROUP BY BUILDINGLANE, BUILDINGNO 
    Order by (SUM(SESSIONPRICE)/COUNT(BUILDINGNO)) desc 
) 
where rownum <= 2