Question

我有以下3个SQL查询，如下所示：

1- SELECT Player FROM ShotTarget Group By Player

2- SELECT COUNT( Target ) FROM ShotTarget Where Target = 'OnTarget' Group By Player

3- SELECT COUNT( TARGET ) FROM ShotTarget Group By Player

如何将这3个查询全部放在一起？我曾经尝试过工会和工会，但我无法让它发挥作用。

非常感谢帮助。

Answer 1

这就是select子句的用途。你可以在那里有多个列。

SELECT Player, COUNT( TARGET ),
       SUM(case when Target = 'OnTarget' then 1 else 0 end)
FROM ShotTarget
Group By Player;

棘手的是Target = 'OnTarget'。这使用条件聚合（聚合函数中的case语句）。

Answer 2

基本上，你试图获取每个玩家的统计数据，这推断出group by条款。可以通过一些CASE技巧来实现目标射击和其他射击之间的区别：

SELECT   player, 
         COUNT (target) AS total_shots
         COUNT (CASE target WHEN 'OnTarget' THEN 1 ELSE NULL END) AS shots_on_target
FROM     ShotTarget
GROUP BY player

注意：COUNT会忽略NULL个值 - 这是shots_on_target计算的基础。

Answer 3

SELECT p.player, COUNT(st.target)
FROM player p
    JOIN ShotTarget st ON st.player = p.player
WHERE st.Target = 'OnTarget'
GROUP BY p.player

在多个SQL语句中使用Count（）并使用join连接它们

3 个答案: