这只是我的头顶,而且我正要出门,所以未经测试。我也无法想象它会在任何种类的大数据集上表现出色。我确实确认它至少可以正常运行。:)
SELECT
value_column1,
(
SELECT
AVG(value_column1) AS moving_average
FROM
Table1 T2
WHERE
(
SELECT
COUNT(*)
FROM
Table1 T3
WHERE
date_column1 BETWEEN T2.date_column1 AND T1.date_column1
) BETWEEN 1 AND 20
)
FROM
Table1 T1