如何在Oracle中聚合多行多列？

Question

我有一个包含三列的表（名为“游戏”）：天气、体育和客户

weather sports       customer
sun     volleyball   Randy 
sun     volleyball   Lau
sun     gym          Ryan
sun     gym          Rachel

表格

weather sports       customer
sun     volleyball   Randy, Lau
sun     gym          Ryan, Rachel

我使用了以下 LISTAGG 命令，但它给了我错误提示“不是按表达式分组”

SELECT
    weather, sports,
    LISTAGG(customer, ',') WITHIN GROUP (ORDER BY sports) "Customer"
    FROM games
    GROUP BY customer;

Answer 1

GROUP BY 需要包含 未聚合的 列。他们定义结果集中的每一行：

SELECT weather, sports,
       LISTAGG(customer, ',') WITHIN GROUP (ORDER BY sports) as Customers
FROM games
GROUP BY weather, sports;