我有这张表:
UNIQUE_ID | WINNER_ID | FINALIST_ID
________1 | ________1 | __________2
________2 | ________1 | __________3
________3 | ________3 | __________1
________4 | ________1 | __________2
我需要所有玩家(获胜者和决赛入围者)的列表以及他们获得第一名或第二名的次数。
在这种情况下，它将是:
PLAYER_ID | WINNER_TIMES | FINALIST_TIMES
________1 | ___________3 | _____________1
________2 | ___________0 | _____________2
________3 | ___________1 | _____________1
这里已经提出了类似的问题( LINK )，但我不明白答案。
最佳答案
select coalesce(winner_id, finalist_id) as PLAYER_ID
, count(winner_id) as WINNER_TIMES
, count(finalist_id) as FINALIST_TIMES
from (
select winner_id
, null as finalist_id
from YourTable
union all
select null
, finalist_id
from YourTable
) as SubQueryAlias
group by
coalesce(winner_id, finalist_id)
关于mysql - 对不同列中的值进行分组并计数，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/11073646/