regr_avgx
regr_avgx 介绍
regr_avgx(y, x) - 返回组中非空值对的自变量的平均值,其中 y 是因变量,x 是自变量。
Examples:
> SELECT regr_avgx(y, x) FROM VALUES (1, 2), (2, 2), (2, 3), (2, 4) AS tab(y, x);
2.75
> SELECT regr_avgx(y, x) FROM VALUES (1, null) AS tab(y, x);
NULL
> SELECT regr_avgx(y, x) FROM VALUES (null, 1) AS tab(y, x);
NULL
> SELECT regr_avgx(y, x) FROM VALUES (1, 2), (2, null), (2, 3), (2, 4) AS tab(y, x);
3.0
> SELECT regr_avgx(y, x) FROM VALUES (1, 2), (2, null), (null, 3), (2, 4) AS tab(y, x);
3.0
Since: 3.3.0