Question

The table has 4 columns Match, Winning_Player_ID, Losing_Player_ID, Quantity_Points_Exchanged_for_that_match. I would like to in a single query show the total number of points each player won and earned over all matches.

Here is the table

M WIN LOSE QTY  
1 100 201 10  
2 201 100 05  
3 100 201 05  
4 302 100 05  

For output I would like total it in this way in a single query and cannot figure it out.

ID WIN LOSE
100 15 10
201 05 15
302 05 00

Answer 1

SELECT p.player ID,
       (SELECT SUM(QTY) FROM tbl WHERE WIN = p.player) WIN,
       (SELECT SUM(QTY) FROM tbl WHERE LOSE = p.player) LOSE
FROM
    (SELECT DISTINCT WIN player FROM tbl
    UNION
    SELECT DISTINCT LOSE FROM tbl) p