我正在整理一个新项目,我需要做的事情之一是获取假足球(美国)比赛的结果。我在 php 和 mysql 中执行此操作,使用 CodeIgniter 作为我的框架。我的dbfiddle如下:
https://www.db-fiddle.com/f/5Q7QezddpNEGabaia2w5FQ/0
现在,如您所见,每个团队都有一个 home_team_id 和away_team_id 条目。我想做的是有一个查询,该查询只为每个球队获取一个结果(无论他们是主场还是客场)。如果不需要的话,我宁愿不以编程方式处理这些数据。
结果应该类似于以下内容:
SELECT week, home_team_id, away_team_id,
my_score, their_score,
a.team_name as home_team, b.team_name as away_team
FROM nfl_user_matchups nm
LEFT JOIN user_teams a ON nm.home_team_id = a.user_teams_id
LEFT JOIN user_teams b ON nm.away_team_id = b.user_teams_id
WHERE week = 1
预期的最终数据将是这样的(my_score 将是 home_team_id 得分,their_score 将是away_team_id 得分):
+------+--------------+--------------+----------+-------------+
| week | home_team_id | away_team_id | my_score | their_score |
+------+--------------+--------------+----------+-------------+
| 1 | 3 | 9 | 112 | 144 |
+------+--------------+--------------+----------+-------------+
| 1 | 7 | 2 | 85 | 96 |
+------+--------------+--------------+----------+-------------+
| 1 | 1 | 6 | 111 | 114 |
+------+--------------+--------------+----------+-------------+
| 1 | 4 | 5 | 99 | 125 |
+------+--------------+--------------+----------+-------------+
| 1 | 8 | 10 | 140 | 122 |
+------+--------------+--------------+----------+-------------+
最佳答案
您的问题陈述基本上意味着一对相互竞争的球队,即,(1,2)
将被视为与(2,1 )
。处理此类要求的一种方法是确保对于这两支球队之间的任何比赛,我们确保它们的顺序相同。所以,基本上我们得到 Least()
两队中的team id值,始终放在第一个索引中;和 Greatest()
值始终位于第二个(最后一个)索引。值得注意的是,Greatest()
与 Max()
不同。 Max()
函数计算列上的最大值;而Greatest()
通常用于比较一行中的值。
现在,我们可以简单地对此对进行GROUP BY
并根据需要计算聚合。在确定主/客场得分时,您需要使用 CASE .. WHEN
表达式来确定特定行是否具有最少的主场 id,或客场 id:
SELECT
week,
LEAST(home_team_id, away_team_id) AS home_id,
GREATEST(home_team_id, away_team_id) AS away_id,
MAX(CASE
WHEN LEAST(home_team_id, away_team_id) = home_team_id
THEN my_score
ELSE their_score
END) AS home_score,
MAX(CASE
WHEN GREATEST(home_team_id, away_team_id) = away_team_id
THEN their_score
ELSE my_score
END) AS away_score
FROM nfl_user_matchups
WHERE week = 1
GROUP BY
week,
home_id,
away_id;
关于php - 每个团队每周仅获得 "football matchup"的一个结果,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/58090173/