MySQL Select SUM JOIN WHERE 一起不起作用

Question

我有问题。 （SQL初学者）。我有两张桌子。

球员(nr, player_id, team_id, name, points, season)

Teams (team_id, team_name, season) - 有一个唯一的 team_id 但team_name 可以根据不同的赛季而有所不同。

我想在特定赛季中对单个 player_id 的所有点求和，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

这对我来说很完美:) 但是，我不知道如何加入团队表来获得 teams.team_name 对应特定季节与 WHERE clousure 相匹配。在这种情况下，season='2015/2016' 具体而言。如果我想总结 2015/2016 赛季球员的积分，我还需要从 2015/2016 赛季获得 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

如果您不想显示没有匹配球队记录的球员记录，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