如何在mysql中选择赢/输记录答案

【问题标题】：How to select win/loss record in mysql如何在mysql中选择赢/输记录
【发布时间】：2019-12-27 23:56:21
【问题描述】：

我有看起来像这样的桌面“游戏”

| team1_id | team2_id | team1_pts | team2_pts |

     1          3        101        117

     2          5        99         98

我想做选择，从表“团队”中返回团队名称和这样的赢/输记录

| team_name | win | loss 

   Boston     15   11        

   Miami      13   12

我想出了如何获得只有获胜次数的桌子，但不知道如何在同一张桌子上获得胜利和失败。

【问题讨论】：

标签： mysql sql

【解决方案1】：

您可以取消旋转并重新加入：

select t.name, sum(is_win) as num_wins, sum(is_loss) as num_losses
from ((select (case when team1_pts > team2_pts then team1_id else team2_id end) as team_id,
              1 as is_win, 0 as is_loss
       from game g
      ) union all
      (select (case when team1_pts < team2_pts then team1_id else team2_id end) as team_id,
              0, 1
       from game g
      )
     ) g join
     teams t
     on t.team_id = g.team_id
group by t.name

【讨论】：

【解决方案2】：

我认为您应该重新审视您的数据模型。也许GAMES 表有字段GAME_ID, TEAM_ID, POINTS。你可能可以让它与你目前所拥有的一起工作，但它并不理想。

【讨论】：

这应该是评论，而不是答案。

【解决方案3】：

这样就可以了：

select team_id ,
sum(case when Points > 0 then 1 else 0 end) as Win,
sum(case when Points < 0 then 1 else 0 end) as Loss

from
(
select team1_id as team_id , team1_pts - team2_pts as Points from games
union all
select team2_id, team2_pts - team1_pts as Points from games
)tbl
group by team_id

【讨论】：