如何在 Oracle 中聚合具有多个列的多行？

Question

我有一个 table（名为 'games'），它包含三列：天气、体育和客户

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

table待

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

我使用了以下 LISTAGG 命令，但它给我错误提示 'not a group by expression'

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。它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;