SQL用於獲取基於等級最高的用戶和使用效果，以獲得額外的數據

Question

我試圖想出它得到每

• 國名的SQL，
• 代碼，
• 數遊戲，
• 頂級球員的名字和
• 他的身份證
• 基於遊戲表中的SUM（等級）。

我很難根據評分獲得頂級玩家的名字。

SQLFiddle Demo

Answer 1

SELECT x.Country AS CountryName, 
     x.Code, 
     a.totalCount as NumberOfGames, 
     y.Name AS PlayersName, 
     y.ID AS PlayersID, 
     a.totalRating 
FROM (
      SELECT player_ID, Country, COUNT(*) totalCount, SUM(Rating) totalRating 
      FROM Games 
      GROUP BY player_ID, Country 
     ) a 
     INNER JOIN 
     (
      SELECT Country, Max(totaLRating) maxRating 
      FROM 
      (
       SELECT player_ID, Country, SUM(Rating) totalRating 
       FROM Games 
       GROUP BY player_ID, Country 
      ) s 
      GROUP BY Country 
     ) b ON a.Country = b.Country AND 
       a.totalRating = b.maxRating 
     INNER JOIN Country x 
      ON a.Country = x.ID 
     INNER JOIN Players y 
      ON a.player_ID = y.ID 

• SQLFiddle Demo

Answer 2

select top 1 * from games inner join players on games.player_id=players.id inner join country on games.country=country.id order by rating desc 

Answer 3

嘗試此查詢

select 
    c.id as country_id, 
    c.name as Country, 
    c.code as CCode, 
    g.T_Games, 
    p.id as Player_id, 
    p.name as Player 
from country as c 
left join (select country , count(country) as T_Games from games group by country) as g on g.country = c.id 
left join (select id , country , player_id , max(rating) from games group by country) as gl on gl.country = c.id 
left join (select id , name from player) as p on p.id = gl.player_id 

這裏是SQL小提琴

http://sqlfiddle.com/#!2/f74a7/1