SQL z-score 구하기

SQL을 통해서 표준화점수 구하기

$$ z-score = \frac{X_i - Mean(X)}{std(X)} $$

SELECT (T1.values - stats.average) / stats.s AS zvalue
FROM  [TABLE] T1 
CROSS JOIN
(SELECT sttdev(VALUES) AS s, avg(VALUES) AS average FROM [TABLE]) stats;