Question

Have a database with three columns – gamekey, teamed, final score. I am trying to find the score differential for each gamekey.

Gamekey. Teamed. Finalscore
 16      27      21
 16       7      24
 17      22      17   
 17      21      10
 18      15      9
 18      11      3

Desire output would be

Gamekey.   Scorediff
16         3
17         7
18         6

Answer 1

Looks like you want the absolute value of the difference, so you could use;

SELECT Gamekey, max(Finalscore) - min(Finalscore) as Scorediff
FROM TableName
GROUP BY Gamekey

–adding the below for validation you ran (granted the below was tested in SQL Server)

declare @testTable as table(Gamekey int, Teamed int, Finalscore int)

INSERT INTO @testTable values(16,27,21)
INSERT INTO @testTable values(16,7,24)
INSERT INTO @testTable values(17,22,17)   
INSERT INTO @testTable values(17,21,10)
INSERT INTO @testTable values(18,15,9)
INSERT INTO @testTable values(18,11,3)


SELECT Gamekey, max(Finalscore) - min(Finalscore) as Scorediff
FROM @testTable
GROUP BY Gamekey