LeetCode（数据库）- 大满贯数量

Posted 2021-12-23 程序员牧码

题目链接：点击打开链接

题目大意：略。

解题思路：略。

AC 代码

-- 解决方案(1)
with a as (
select player_id, sum(
if(wimbledon=player_id,1,0)+
if(fr_open=player_id,1,0)+
if(us_open=player_id,1,0)+
if(au_open=player_id,1,0)) grand_slams_count
from championships
join (select player_id from players) b
group by player_id
)
select players.player_id,player_name, grand_slams_count
from players
left join a on players.player_id=a.player_id 
having grand_slams_count>0

-- 解决方案(2)
WITH t AS(SELECT Wimbledon player_id, COUNT(*) cnt
FROM Championships c
GROUP BY Wimbledon

UNION ALL

SELECT Fr_open, COUNT(*) cnt
FROM Championships c
GROUP BY Fr_open

UNION ALL

SELECT US_open, COUNT(*) cnt
FROM Championships c
GROUP BY US_open

UNION ALL

SELECT Au_open, COUNT(*) cnt
FROM Championships c
GROUP BY Au_open)

SELECT player_id, player_name, SUM(cnt) grand_slams_count
FROM t JOIN Players USING(player_id)
GROUP BY player_id