SQL查询以获取不同年份但具有一致数据的已售零件总数

Question

I have a sales order database that contains entries on items sold. I want to display the totals for each part sold for both the current year and previous two years. My current query is shown below. (It is searching for part numbers ending in a 'k' which is a special type of part in our database.)

SELECT DISTINCT PRTNUM_28, sum(SHPQTY_28) AS TOTAL, PM.PMDES1_01
FROM   SO_Detail SOD
           JOIN PART_MASTER PM ON SOD.PRTNUM_28 = PM.PRTNUM_01
WHERE PRTNUM_28 LIKE '%k'
AND   SHPDTE_28 > '2011'
AND   SHPDTE_28 < '2012'
GROUP BY PRTNUM_28, PM.PMDES1_01
ORDER BY TOTAL DESC, PRTNUM_28

The above query works fine to display the totals for each part number for 2012, but how do I also include the data from the previous two years in the same result?

Note that for each year, part numbers may or may not exist - ie 2011 may contain a part that wasn't sold in 2012 or 2010 and similarly 2011 may not contain a part that was sold in 2012 and/or 2010. I'm not sure how to achieve this query.

Answer 1

Assuming that you also want to break it out by year, then its probably something like this:

SELECT LEFT(SHPDTE_28,4) As YR, PRTNUM_28, sum(SHPQTY_28) AS TOTAL, PM.PMDES1_01
FROM SO_Detail SOD
JOIN PART_MASTER PM ON SOD.PRTNUM_28 = PM.PRTNUM_01
WHERE PRTNUM_28 LIKE '%k'
AND SHPDTE_28 > '2009'
AND SHPDTE_28 < '2012'
GROUP BY LEFT(SHPDTE_28,4), PRTNUM_28, PM.PMDES1_01
ORDER BY TOTAL DESC, PRTNUM_28, YR

I cannot be sure though without the table definitions.

(Note also that you do not normally use DISTINCT with GROUP BY as its redundant.)

Answer 2

I am not sure what RDBMS you are using but you can alter this for any. The DatePart function is specific for SQL Server.

But, if you want to display the data for each year in a separate column, then you can use something like this, which basically pivots the data for each year:

SELECT 
  PRTNUM_28, 
  sum(case when DatePart(yy, SHPDTE_28) = 2009 then SHPQTY_28 end) AS Total_2009, 
  sum(case when DatePart(yy, SHPDTE_28) = 2010 then SHPQTY_28 end) AS Total_2010, 
  sum(case when DatePart(yy, SHPDTE_28) = 2011 then SHPQTY_28 end) AS Total_2011, 
  sum(case when DatePart(yy, SHPDTE_28) = 2012 then SHPQTY_28 end) AS Total_2012,
  PM.PMDES1_01
FROM SO_Detail SOD
LEFT JOIN PART_MASTER PM 
  ON SOD.PRTNUM_28 = PM.PRTNUM_01
WHERE PRTNUM_28 LIKE '%k'
  AND SHPDTE_28 > '2009'
  AND SHPDTE_28 < '2012'
GROUP BY DatePart(yy, SHPDTE_28), PRTNUM_28, PM.PMDES1_01;

Or if you have access to a PIVOT function, you can also use the following:

select *
from
(
  SELECT DatePart(yy, SHPDTE_28) As YR, 
    PRTNUM_28, 
    SHPQTY_28,
    PM.PMDES1_01
  FROM SO_Detail SOD
  LEFT JOIN PART_MASTER PM 
    ON SOD.PRTNUM_28 = PM.PRTNUM_01
  WHERE PRTNUM_28 LIKE '%k'
    AND SHPDTE_28 > '2009'
    AND SHPDTE_28 < '2012'
) src
pivot
(
  sum(SHPQTY_28)
  for yr in ([2009], [2010], [2011], [2012])
) piv