Question

我有问题。（SQL begginer）。我有两张桌子。

玩家（nr，player_id，team_id，姓名，积分，季节）

团队（team_id，team_name，season） - Ther是一个独特的team_id但是team_name可以根据不同的赛季而有所不同。

我想在特定赛季中记录单个球员_id的所有积分，我可以这样做:)

    SELECT SUM(players.points), 
           players.player_id, 
           players.team_id, 
           players.season,
           players.nr, 
           players.name 
      FROM players 
     WHERE season='2015/2016' 
  GROUP BY player_id 
  ORDER BY SUM(players.points) DESC 
     LIMIT 30

这项工作对我来说很完美:)但是，我无法想象如何加入团队表来获取 teams.team_name对应于特定季节与WHERE clousure相匹配。在这种情况下，赛季=＆＃39; 2015/2016＆＃39;要有特色。如果我想从2015/2016获得积分，我需要从seasson 2015/2016获得team_name。我尝试了LEFT JOIN但没有成功：/ 这是我的代码。

    SELECT players.player_id, 
           players.nr, 
           players.name, 
           players.team_id, 
           SUM(players.points), 
           players.season 
      FROM players 
     WHERE players.sezon='2015/2016' 
 LEFT JOIN teams 
        ON (teams.team_id=players.team_id AND teams.season=players.season ) 
  GROUP BY player_id 
  ORDER BY SUM(points) DESC 
     LIMIT 30

感谢您的努力。

Answer 1

如果您不想在没有匹配球队记录的情况下显示球员记录，请使用INNER JOIN而不是LEFT JOIN

SELECT players.player_id, 
       players.nr, 
       players.name, 
       players.team_id, 
       SUM(players.points), 
       players.season,
       teams.team_name
FROM players 
LEFT JOIN teams 
    ON (teams.team_id = players.team_id AND teams.season = players.season ) 
WHERE players.season = '2015/2016' 
GROUP BY player_id 
ORDER BY SUM(points) DESC 
LIMIT 30

MySQL选择SUM JOIN WHERE一起不工作

1 个答案: