Question

我想只显示前2个建筑物及其相应的会话平均价格。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));

但我得到第3行的错误“SQL命令没有正确结束”，但是如果我用分号结束第3行，我得到第1行的“不是单组组函数”的新错误。我不确定我哪里出错了，我试过这个搜索但我没有运气解决这个问题。

感谢任何帮助！

Answer 1

您应该使用Order by代替Where子句

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

错误不是单个组组功能

2 个答案: