राशि के लिए कस्टम गणना

यहां एक वैकल्पिक दृष्टिकोण है जिसके लिए LAG() की आवश्यकता है जो SQL 2012 से उपलब्ध है, लेकिन ध्यान दें कि नमूना डेटा में प्रत्येक तिथि से पहले "28 अलग-अलग दिन" नहीं होते हैं। इसके अलावा वास्तविक डेटा प्रकार का उपयोग किया जा रहा है (दिनांक/स्मॉलडेटटाइम/डेटाटाइम/डेटाटाइम 2) और न ही यह ज्ञात है कि तिथि से समय को कम करने की आवश्यकता है या नहीं। तो कुछ चेतावनियों के साथ, यह दृष्टिकोण 28 अलग-अलग तिथियों के लिए दिनांक सीमाओं की एक श्रृंखला बनाता है (लेकिन क्या डेटा इन्हें प्रदान नहीं करता है तो वे 28 बीत चुके दिन हैं)। यह रहा एक sqlfiddle डेमो

PostgreSQL 9.3 स्कीमा सेटअप :(जैसा कि SQL सर्वर sqlfiddle पर काम नहीं कर रहा है)

CREATE TABLE Table1
    (theDate timestamp, Value int, promo int, item int)
;

INSERT INTO Table1
    (theDate, Value, promo, item)
VALUES
    ('2011-01-01 00:00:00', 626, 0, 1230),
    ('2011-01-02 00:00:00', 231, 1, 1230),
    ('2011-01-03 00:00:00', 572, 1, 1230),
    ('2011-01-04 00:00:00', 775, 1, 1230),
    ('2011-01-05 00:00:00', 660, 1, 1230),
    ('2011-01-06 00:00:00', 662, 1, 1230),
    ('2011-01-07 00:00:00', 541, 1, 1230),
    ('2011-01-08 00:00:00', 849, 1, 1230),
    ('2011-01-09 00:00:00', 632, 1, 1230),
    ('2011-01-10 00:00:00', 906, 1, 1230),
    ('2011-01-11 00:00:00', 961, 1, 1230),
    ('2011-01-12 00:00:00', 361, 0, 1230),
    ('2012-01-01 00:00:00', 461, 0, 1230),
    ('2012-01-02 00:00:00', 928, 1, 1230),
    ('2012-01-03 00:00:00', 855, 0, 1230),
    ('2012-01-04 00:00:00', 605, 0, 1230),
    ('2012-01-05 00:00:00', 83, 0, 1230),
    ('2012-01-06 00:00:00', 44, 0, 1230),
    ('2012-01-07 00:00:00', 382, 0, 1230),
    ('2012-01-08 00:00:00', 862, 0, 1230),
    ('2012-01-09 00:00:00', 549, 0, 1230),
    ('2012-01-10 00:00:00', 632, 0, 1230),
    ('2012-01-11 00:00:00', 2, 0, 1230),
    ('2012-01-12 00:00:00', 26, 0, 1230)
;

क्वेरी 1 :

select
      t1.item
    , ranges.theStart
    , ranges.theEnd
    , sum(t1.value)
    , sum(t1.value) / 28 avg
from (
      select
            coalesce(lag(theDay,28) over(order by theDay) , theDay - INTERVAL '28 DAYS') as theStart
          , theDay as theEnd
      from (
            select distinct cast(thedate as date) theDay from Table1
            ) days
      ) ranges
inner join table1 t1 on theDate between ranges.theStart and ranges.theEnd
group by
      t1.item
    , ranges.theStart
    , ranges.theEnd

परिणाम :

| item |                   thestart |                    theend |  sum | avg |
|------|----------------------------|---------------------------|------|-----|
| 1230 | December, 04 2010 00:00:00 | January, 01 2011 00:00:00 |  626 |  22 |
| 1230 | December, 05 2010 00:00:00 | January, 02 2011 00:00:00 |  857 |  30 |
| 1230 | December, 06 2010 00:00:00 | January, 03 2011 00:00:00 | 1429 |  51 |
| 1230 | December, 07 2010 00:00:00 | January, 04 2011 00:00:00 | 2204 |  78 |
| 1230 | December, 08 2010 00:00:00 | January, 05 2011 00:00:00 | 2864 | 102 |
| 1230 | December, 09 2010 00:00:00 | January, 06 2011 00:00:00 | 3526 | 125 |
| 1230 | December, 10 2010 00:00:00 | January, 07 2011 00:00:00 | 4067 | 145 |
| 1230 | December, 11 2010 00:00:00 | January, 08 2011 00:00:00 | 4916 | 175 |
| 1230 | December, 12 2010 00:00:00 | January, 09 2011 00:00:00 | 5548 | 198 |
| 1230 | December, 13 2010 00:00:00 | January, 10 2011 00:00:00 | 6454 | 230 |
| 1230 | December, 14 2010 00:00:00 | January, 11 2011 00:00:00 | 7415 | 264 |
| 1230 | December, 15 2010 00:00:00 | January, 12 2011 00:00:00 | 7776 | 277 |
| 1230 | December, 04 2011 00:00:00 | January, 01 2012 00:00:00 |  461 |  16 |
| 1230 | December, 05 2011 00:00:00 | January, 02 2012 00:00:00 | 1389 |  49 |
| 1230 | December, 06 2011 00:00:00 | January, 03 2012 00:00:00 | 2244 |  80 |
| 1230 | December, 07 2011 00:00:00 | January, 04 2012 00:00:00 | 2849 | 101 |
| 1230 | December, 08 2011 00:00:00 | January, 05 2012 00:00:00 | 2932 | 104 |
| 1230 | December, 09 2011 00:00:00 | January, 06 2012 00:00:00 | 2976 | 106 |
| 1230 | December, 10 2011 00:00:00 | January, 07 2012 00:00:00 | 3358 | 119 |
| 1230 | December, 11 2011 00:00:00 | January, 08 2012 00:00:00 | 4220 | 150 |
| 1230 | December, 12 2011 00:00:00 | January, 09 2012 00:00:00 | 4769 | 170 |
| 1230 | December, 13 2011 00:00:00 | January, 10 2012 00:00:00 | 5401 | 192 |
| 1230 | December, 14 2011 00:00:00 | January, 11 2012 00:00:00 | 5403 | 192 |
| 1230 | December, 15 2011 00:00:00 | January, 12 2012 00:00:00 | 5429 | 193 |

ध्यान दें:SQL सर्वर के लिए

• theDay - INTERVAL '28 DAYS' dateadd(दिन,-28,दिन) . का उपयोग करें