Question

First, I know that’s a terribly vague title — my knowledge of SQL is so weak that I don’t really know the particulars of what I’m asking, so please bear with me.

I have a table that looks like this:

+--------+-----------+----------+--------+--------+
| gameid | team1     | team2    | score1 | score2 |
+--------+-----------+----------+--------+--------+
|      1 | New York  | Boston   |      1 |      2 |
|      2 | New York  | Boston   |      2 |      0 |
|      3 | Baltimore | New York |      3 |      1 |
|      4 | Boston    | New York |      3 |      0 |
+--------+-----------+----------+--------+--------+

Where gameid is a unique identifier, score1 corresponds to the score for team1, etc.

What I need is a query that will produce a summation of wins and losses for a given team against all opponents. Using New York for example, the query would create the following table:

+-----------+------+--------+
| team      | wins | losses |
+-----------+------+--------+
| Baltimore |    0 |      1 |
| Boston    |    1 |      2 |
+-----------+------+--------+

Answer 1

I don’t have access to a SQL box right now (so this may be syntax-weak) and I’m not a huge fan of the db structure but this ought to get you going:

SELECT team, SUM(win) AS wins, SUM(loss) AS losses
FROM
 (SELECT team1 AS team, 
   CASE WHEN score1>score2 THEN 1 END AS win, 
   CASE WHEN score2>score1 THEN 1 END AS loss
  FROM YourTable
  UNION ALL
  SELECT team2 AS team, 
   CASE WHEN score2>score1 THEN 1 END AS win, 
   CASE WHEN score1>score2 THEN 1 END AS loss
  FROM YourTable)
GROUP BY team

Also, this ignores ties.

Note: I made this CW–please update if you can improve it