MySql为体育联赛划分.pct

出于某种原因，我无法写出一段简单的代码

我想在下面的代码中将“赢”除以“玩”，这样在我的输出中，如果你赢了4场比赛中的2场，那么它显示为.500

当然，这很简单，一个位置可能是关键，但我无法理解它为我的生活

$result = mysql_query("
    select team, 
    count(*) played, 
    count(case when HomeScore > AwayScore then 1 end) wins, 
    count(case when AwayScore > HomeScore then 1 end) lost, 
    count(case when HomeScore = AwayScore then 1 end) draws,
    sum(HomeScore) ptsfor, 
    sum(AwayScore) ptsagainst,
    sum(HomeScore) - sum(AwayScore) goal_diff, 
    sum(case when HomeScore > AwayScore then 3 else 0 end + case 
    when HomeScore = AwayScore then 1 else 0 end) score     
    from (select 
        HomeTeam team, 
        HomeScore, 
        AwayScore 
    from Game 
        union all 
    select  AwayTeam, 
        AwayScore, 
        HomeScore 
    from Game) a 
    group by team 
    order by wins desc, 
         draws desc,
     lost asc,
     goal_diff desc;");

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谢谢，只需向查询中添加另一个计算列，如下所示：

select team, 
count(*) played, 
count(case when HomeScore > AwayScore then 1 end) wins,
(cast(count(case when HomeScore > AwayScore then 1 end) as decimal(8,2)/cast(count(*) as decimal(8,2)) percentage,
.... -> Rest of the query goes here

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因为我假设分数是整数，所以选角就完成了。如果不进行强制转换，则会丢失准确性，即2/4将在不进行强制转换的情况下返回0。

请尝试下面的查询。这充分利用了MySQL的行为，将布尔表达式自动转换为int。因此，这意味着不需要CASE语句，也不需要以牺牲可移植性为代价的查询。此外，像SUM3*win+draw score这样的部件在视觉上看起来更像您的分数计算公式。计算pct没有问题

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我现在得到警告：mysql_fetch_assoc期望参数1是resource，布尔值在第41行的/home/peterborough/www/www/leaguetable.php中给出，这是我的while stmt，它以前工作过：while$row=mysql_fetch_assoc$result{echo；echo.$row['team']；echo.$row['wins']；echo.$row['lost']；echo.$row['percentage']；echo；}echo；这看起来更像是这样，虽然对于一支赢了4/5场比赛的球队来说，它显示为.4000，而它应该是.800。我们需要找出如何使它成为小数点后3位，而不是4毫米。在我的测试中，我有一支赢了4/5场比赛的球队，并且正确显示为0.8000。我不知道它怎么会变成0.4000。我只是把模式放在SQL FIDLE中。。。至于十进制精度，这实际上更多的是在表示/客户端。您可以通过应用程序控制要显示的位置，例如：PHP。

SELECT team
     , COUNT(*)  played
     , SUM(win)  wins
     , SUM(loss) lost
     , SUM(win)/count(*) pctWon
     , SUM(draw) draws
     , SUM(SelfScore) ptsfor
     , SUM(OpponentScore) ptsagainst
     , SUM(SelfScore) - SUM(OpponentScore) goal_diff
     , SUM(3*win + draw) score
FROM (
      SELECT team
     , SelfScore
     , OpponentScore
     , SelfScore < OpponentScore win
     , SelfScore > OpponentScore loss
     , SelfScore = OpponentScore draw
      FROM (
        SELECT HomeTeam team, HomeScore SelfScore, AwayScore OpponentScore
        FROM Game
        union all select AwayTeam, AwayScore, HomeScore
        FROM Game
       ) a
) b
GROUP BY team
ORDER BY wins DESC, draws DESC, lost ASC, goal_diff DESC;