Question

I’m trying to come up with an SQL which gets every

• country’s name,
• code,
• number of games,
• TOP player’s name and
• his id
• based on the SUM(rating) in the games table.

I’m having trouble with getting the name of the top player based on the rating.

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