Question

让您了解我正在尝试做什么。简化的表结构将是：

homeTeamName | awayTeamName | homeTeamGoals | awayTeamGoals
-----------------------------------------------------------
Team1        | Team2        |      4        |       3
Team1        | Team3        |      0        |       1
Team3        | Team2        |      0        |       0

数据来自足球比赛。我想要做的是检索'形式'团队，即赢得了大多数游戏的团队（假设上表中填充了更多数据）。如果我想要检索特定团队的“胜利计数”，那么查询就相当容易了，如下所示。

SELECT COUNT(*) as winCount FROM matches_new 
  WHERE (
      homeTeamName = 'Team1' AND 
      homeTeamGoals > awayTeamGoals
    ) OR (
      awayTeamName = 'Team1' AND 
      awayTeamGoals > homeTeamGoals
    )
  ORDER BY winCount DESC LIMIT 1

该查询将返回特定团队可能拥有的“胜利”数量。现在我想做的是我的查询检查所有球队然后返回拥有最多“胜利”的球队的名称以及“胜利”（胜利数）的数量。

我真的不知道怎么做！我已经尝试了很多搜索，但很难想到如何描述这种类型的任务，或者想到任何类似的任务。我的麻烦似乎源于这样一个事实：我不知道你怎么做WHERE子句而不具体说明值应该等于什么。

感谢。

Answer 1

您可以使用案例陈述：

select winningTeam, count(*) as winCount from (
    select case 
             when homeTeamGoals > awayTeamGoals then homeTeamName
             when awayTeamGoals > homeTeamGoals then awayTeamName
             else null
           end as winningTeam
        from matches_new
  ) winners
  where winningTeam is not null
  group by winningTeam
  order by winCount desc limit 1

或者你可以用工会来解决它：

SELECT teamName, COUNT(*) as winCount from (
     select homeTeamName as teamName from  matches_new 
        WHERE homeTeamGoals > awayTeamGoals
     union all
     select awayTeamName as teamName from  matches_new 
        WHERE awayTeamGoals > homeTeamGoals
  ) as allWinners
  GROUP BY teamName
  ORDER BY winCount DESC LIMIT 1

Answer 2

试试这个

select teamname, count(*) winCount from 
(
select case when homeTeamGoals > awayTeamGoals then hometeamname
            when wayTeamGoals > homeTeamGoals then awayTeamName end Teamname
from matches_new
where (homeTeamGoals > awayTeamGoals or wayTeamGoals > homeTeamGoals)
)
group by teamname
ORDER BY winCount DESC LIMIT 1

如何检索与某个WHERE条件匹配的每组记录的计数？

2 个答案: