Bosconian wrote:
> SELECT mr.teamid,
> SUM( IF( mr.winner = '1', 1, 0 ) ) AS wins,
> SUM( IF( mr.winner = '0', 1, 0 ) ) AS losses,
> SUM(wins/losses) AS percentage <----- how to correctly calculate
> FROM match_result mr
> GROUP BY mr.teamid

Would this do what you want?

SELECT mr.teamid,
SUM( IF( mr.winner = '1', 1, 0 ) ) / COUNT(mr.winner) AS wins_pct,
SUM( IF( mr.winner = '0', 1, 0 ) ) / COUNT(mr.winner) AS losses_pct,
FROM match_result mr
GROUP BY mr.teamid

Unfortunately, we cannot reference column aliases in other expressions
in the select-list. We can reference column aliases only in GROUP BY,
ORDER BY, or HAVING clauses. See
http://dev.mysql.com/doc/refman/5.0/...ith-alias.html

Regards,
Bill K.