MariaDB 10.2

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CREATE TABLE scorecards
(
    score_week int
    , score_user int
    , score int
);

INSERT INTO scorecards (score_week, score_user, score)
VALUES (1, 1, 100)
    , (1, 2, 50)
    , (1, 3, 75)
    , (2, 1, 20)
    , (2, 2, 30)
    , (2, 3, 40);

SELECT s.score_week
    , User1 = sum(s.user1)
    , User2 = sum(s.user2)
    , User3 = sum(s.user3)
FROM (
    SELECT s.score_week
        , CASE WHEN s.score_user = 1 THEN SUM(s.score) ELSE 0 END AS User1
        , CASE WHEN s.score_user = 2 THEN SUM(s.score) ELSE 0 END AS User2
        , CASE WHEN s.score_user = 3 THEN SUM(s.score) ELSE 0 END AS User3
    FROM scorecards s
    GROUP BY s.score_week
        , s.score_user
    ) s
GROUP BY s.score_week;


score_week
User1 = sum(s.user1)
User2 = sum(s.user2)
User3 = sum(s.user3)


1
1
0
0

2
1
0
0