self join plus another join

Question

I have a table of country teams

id  country  group
1   Poland   1
2   Greece   1
3   England  2
4   France   2
5   Germany  3
6   Spain    3

I also a table of scores for each country

fromId  score
1       100
3       50
2       90
4       60

What I would like to do is get back a table of scores for each country within a group, having supplied just a country name. For example if I supply "France" then I would want the following table back

country   score
England   50
France    60

I have managed to self join the country table with

SELECT
`t1`.`fldCountry`,
`t1`.`fldID`
FROM tblteam t1, tblteam t2
WHERE
t2.fldTeam = t1.fldTeam
AND
t2.fldCountry = 'France'

but am now stuck how to joing this back to get the data!

Please could anyone help a little?

Answer 1

Here you go

Country Table:

CREATE TEMPORARY TABLE Country
    (
      id INT,
      country VARCHAR(20),
      grp INT
    )
INSERT  INTO  Country
        (
          id,
          country,
          grp
        )
        SELECT  1,
                'Poland',
                1
        UNION ALL
        SELECT  2,
                'Greece',
                1
        UNION ALL
        SELECT  3,
                'England',
                2
        UNION ALL
        SELECT  4,
                'France',
                2
        UNION ALL
        SELECT  5,
                'Germany',
                3
        UNION ALL
        SELECT  6,
                'Spain',
                3 

Score Table:

CREATE TEMPORARY TABLE Score ( fromid INT, score INT )
INSERT  INTO Score
        (
          fromid,
          score
        )
        SELECT  1,
                100
        UNION ALL
        SELECT  3,
                50
        UNION ALL
        SELECT  2,
                90
        UNION ALL
        SELECT  4,
                60 

Query:

SELECT  b.country,
        IFNULL(s.score, 0) score
FROM    Country a
        INNER JOIN Country b
            ON a.grp = b.grp
        LEFT JOIN score s
            ON s.fromid = b.id
WHERE   a.country = 'France'

Result:

Country      Score
England      50
France       60

Answer 2

SELECT
    c.country,
    s.score
FROM
    countries c
    INNER JOIN scores s ON c.id = s.fromId
WHERE
    c.group = (SELECT group FROM countries WHERE country = 'France' LIMIT 1);

Answer 3

Something like this should work.

Select C2.Country,SUM(S.Score)
FROM Country AS C1 
INNER JOIN Country AS C2
ON C1.Group=C2.Group
INNER JOIN Scores AS S
ON C2.id = S.FromID 
WHERE C1.Country=@Country
GROUP BY C2.Country

Where @Country is the country you want to look up, in your case, France.