计算查询中的分钟数

Question

我正在寻找一种方法来计算我的团队中每位球员（或这里只有一名球员）的上场时间。简化的数据库表如下：

matchid    action    minute    player
-------------------------------------
1          subbedin  30        Pele 
2          starter             Pele
2          subbedout 50        Pele
3          subbedin  70        Pele
3          red       80        Pele
4          starter             Pele

我现在对其他统计数据的查询：

$query = mysql_query("SELECT *,
  SUM(CASE WHEN action = 'starter' OR action = 'subbedin' THEN 1 ELSE 0 END) AS games,
  SUM(CASE WHEN action = 'goal' OR action = 'pengoal' THEN 1 ELSE 0 END) AS goals,
  SUM(CASE WHEN action = 'yellow' THEN 1 ELSE 0 END) AS yellows,
  SUM(CASE WHEN action = 'red' THEN 1 ELSE 0 END) AS reds,
  // MINS GOES HERE
FROM league2012
GROUP BY player");

对于每个 matchid，基本计算是

( 90 OR subbedout OR red ) - ( starter OR subbedin )

例如在第二场比赛中

subbedout (50) - starter (0) = 50

最后表格应该是这样的：

player    minutes    goals, cards, etc.
---------------------------------------
Pele      210        ...

过去一个小时我一直在阅读教程，但似乎无法弄清楚如何去做。

Answer 1

我会首先计算每个球员在每场比赛中的上场时间，然后将它们相加得到每个球员的总时间。要将获得的结果与您正在计算的其他统计数据结合起来，我认为没有其他方法只能以相同的方式进行其他统计，即首先是每个球员和比赛，然后是每个球员。这就是我的意思：

SELECT
  player,
  SUM(games) AS games,
  SUM(goals) AS goals,
  SUM(yellows) AS yellows,
  SUM(reds) AS reds,
  SUM(minutesplayed) AS minutesplayed
FROM (
  SELECT
    player,
    matchid,
    SUM(CASE WHEN action IN ('starter', 'subbedin') THEN 1 ELSE 0 END) AS games,
    SUM(CASE WHEN action IN ('goal', 'pengoal') THEN 1 ELSE 0 END) AS goals,
    SUM(CASE WHEN action = 'yellow' THEN 1 ELSE 0 END) AS yellows,
    SUM(CASE WHEN action = 'red' THEN 1 ELSE 0 END) AS reds,
    IFNULL(SUM(CASE WHEN action IN ('subbedout', 'red') THEN minute END), 90)
    - IFNULL(SUM(CASE WHEN action = ('subbedin') THEN minute END), 0) AS minutesplayed
  FROM league2012
  GROUP BY
    player,
    matchid
) s
GROUP BY
  player

Answer 2

  sum
    (
      case action
        when 'subbedin'  then 90 - minute
        when 'starter'   then 90
        when 'subbedout' then minute - 90
        when 'red'       then minute - 90
      end
    ) as minutes