MySql爲體育聯盟的.pct劃分

Question

出於某種原因，我不能簡單地介紹一些代碼。

我想在下面的代碼中將「贏」分爲「玩」，這樣在我的輸出中，如果您贏得了4場比賽中的2場比賽，則顯示爲.500？

確定它很簡單，放置可能是關鍵，但我無法爲我的生活摸索它！

$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;"); 

感謝

Answer 1

又一個計算列添加到查詢，像這樣：因爲我假定分數將是整數

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 

鑄造完成。如果沒有施法，將會失去準確性，即2/4將在沒有施法的情況下返回0。

Answer 2

請嘗試以下的查詢。這利用了MySQL的行爲自動將boolean表達式轉換爲int。所以這意味着沒有CASE語句（漂亮的查詢以犧牲可移植性爲代價）。此外，SUM(3*win + draw) score等部件在視覺上看起來更像您的分數計算公式。計算沒問題pct。

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;