我有一个表(日期,有效载荷),其中包含大约10年的数据,我想根据14天(2周)和90天(12天)计算显示有效载荷趋势的移动平均值(MA)周间隔
我写了这个查询,但它给我错误的值
SELECT x.*,
ABS (LTMA-STMA) DIFFERECNE
FROM
(SELECT SDATE,
PAYLOAD,
AVG(PAYLOAD) OVER (ORDER BY W ROWS BETWEEN 2 PRECEDING AND CURRENT ROW) STMA,
AVG(PAYLOAD) OVER (ORDER BY W ROWS BETWEEN 12 PRECEDING AND CURRENT ROW) LTMA
FROM
(SELECT b.*,
TO_NUMBER(TO_CHAR( X.SDATE, 'W')) W
FROM
(SELECT TO_DATE(TO_CHAR(a.SDATE, 'YYYY-MM-DD'), 'YYYY-MM-DD') SDATE,
SUM(a.PAYLOAD) PAYLOAD
FROM TABLE_PAYLOAD a
WHERE a.SDATE > sysdate - 3 * 365
GROUP BY TO_CHAR(a.SDATE, 'YYYY-MM-DD')
ORDER BY TO_CHAR(a.SDATE, 'YYYY-MM-DD')
) b )
ORDER BY SDATE
) x;
其实我知道MA
是什么,但我不明白Oracle是如何工作的!
我可以在Excel中计算MA
,但我需要在数据库级别执行此操作,请您告诉我该怎么做?
答案 0 :(得分:3)
我不明白使用TO_CHAR(SDATE, 'W')
有什么意义?根据文件,这应该是给你一个月的周数......
无论如何,我试图简化查询,希望它仍然符合您的需求:
SELECT x.*, ABS (LTMA-STMA) DIFFERENCE
FROM
(
SELECT SDATE, PAYLOAD,
AVG(PAYLOAD) OVER (ORDER BY SDATE rows BETWEEN 14 PRECEDING AND CURRENT ROW) STMA,
AVG(PAYLOAD) OVER (ORDER BY SDATE rows BETWEEN 90 PRECEDING AND CURRENT ROW) LTMA
FROM
(
SELECT a.SDATE, SUM(a.PAYLOAD) PAYLOAD
FROM TABLE_PAYLOAD a
WHERE a.SDATE > sysdate - 3 * 365
GROUP BY a.SDATE
)
) x
ORDER BY SDATE;
PS:我没有看到TO_DATE(TO_CHAR(a.SDATE, 'YYYY-MM-DD'), 'YYYY-MM-DD')
这一点,这相当于a.SDATE
......