如何在时态数据库中应用移动平均线。 我的数据包括温度,我想为每15条记录应用移动平均线。
答案 0 :(得分:3)
您可以按以下方式触发查询
marc=# SELECT entity, name, salary, start_date,
avg(salary) OVER (ORDER BY entity, start_date
ROWS BETWEEN 1 PRECEDING AND 1 FOLLOWING)
FROM salary;
entity | name | salary | start_date | avg
-----------+-----------+---------+---------------+----------------------
Accounting | millicent | 850.00 | 2006-01-01 | 825.0000000000000000
Accounting | jack | 800.00 | 2010-05-01 | 916.6666666666666667
R&D | tom | 1100.00 | 2005-01-01 | 966.6666666666666667
R&D | john | 1000.00 | 2008-07-01 | 933.3333333333333333
R&D | maria | 700.00 | 2009-01-01 | 733.3333333333333333
R&D | kevin | 500.00 | 2009-05-01 | 633.3333333333333333
R&D | marc | 700.00 | 2010-02-15 | 600.0000000000000000
答案 1 :(得分:2)
WITH moving_avrag AS (
SELECT 0 AS [lag] UNION ALL
SELECT 1 AS [lag] UNION ALL
SELECT 2 AS [lag] UNION ALL
SELECT 3 AS [lag] --ETC
)
SELECT
DATEADD(day,[lag],[date]) AS [reference_date],
[otherkey1],[otherkey2],[otherkey3],
AVG([value1]) AS [avg_value1],
AVG([value2]) AS [avg_value2]
FROM [data_table]
CROSS JOIN moving_avg
GROUP BY [otherkey1],[otherkey2],[otherkey3],DATEADD(day,[lag],[date])
ORDER BY [otherkey1],[otherkey2],[otherkey3],[reference_date];