Question

当我尝试执行此查询时，我一直收到此错误，但我无法弄清楚出了什么问题。我正在使用Oracle和JDBC。

以下是查询：

SELECT Temp.flight_number, Temp.avgprice 
FROM (SELECT P.flight_number, AVG (P.amount) AS avgprice 
        FROM purchase P 
       GROUP BY P.flight_number) AS Temp 
WHERE Temp.avgprice = (SELECT MAX (Temp.avgprice) 
                         FROM Temp)

我试图获得客户预订的门票平均价格的最大值，按航空号码分组。

Answer 1

一些问题。

您无法在Oracle中使用AS来为表名设置别名
您不能像那样在子查询中引用别名TEMP。

使用分析函数通常是最有效的方法。

SELECT flight_number,
       avgprice
  FROM (
    SELECT t.flight_number, 
           t.avgprice,
           rank() over (order by t.avgprice desc) rnk
      FROM (SELECT P.flight_number, 
                   AVG (P.amount) AS avgprice 
              FROM purchase P 
             GROUP BY P.flight_number) t
    )
 WHERE rnk = 1

您还可以使用子查询因子分析来执行此类操作

WITH temp AS (
  SELECT P.flight_number, 
         AVG (P.amount) AS avgprice 
   FROM purchase P 
  GROUP BY P.flight_number 
)
SELECT flight_number,
       avgprice
  FROM temp
 WHERE avgprice = (SELECT MAX(avgprice)
                     FROM temp)

Answer 2

SELECT Temp.flight_number, Temp.avgprice 
FROM (SELECT P.flight_number, 
             AVG (P.amount) AS avgprice 
      FROM purchase P 
      GROUP BY P.flight_number) Temp 
WHERE Temp.avgprice = (SELECT MAX (Temp1.avgprice) 
                       FROM (SELECT P.flight_number,
                                    AVG(P.amount) AS avgprice 
                             FROM purchase P 
                             GROUP BY P.flight_number) temp1
                       );

SQL命令未正确结束（嵌套聚合与分组）

2 个答案: