计算查询中的分钟数

Question

I'm looking for a way to count the amount of minutes each player (or here just one) in my team has played. Simplified database table is as follows:

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

The query I have right now for the other stats:

$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");

For every matchid the basic calculation is

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

For example in match 2

subbedout (50) - starter (0) = 50

In the end the table should looke like this:

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

I've been going through tutorials for the past hour and can't seem to figure out how to do it.

Answer 1

  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

Answer 2

I would first calculated minutes played by every player for every match, add them up to obtain the totals per player. To combine the obtained results with the other stats you are calculating, I can see no other way than to do the other stats in the same way, ie first per player & match, then per player. Here's what I mean:

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