以相同方式汇总同一列

Question

here is my table Prod of monthly production report:

PruID Prod1 Prod2, ReportDate
001 12.5 32.4 1/1/1999
001 13.0 32.0 2/1/1999
...
002 45.2 32.4 1/1/2004
002 56.3 43.2 2/1/2004
...

I want to summarize Prod1 and Prod2, as well as last 12 months of Prod1 & Prod2 by PruID. I wrote 2 separate queries and they are working for each purpose:

Query 1: Summarize prod1 & prod2 by PruID

SELECT Prod.PruID, Sum(Prod.Prod1) AS CumProd1, Sum(Prod.Prod2) AS CumProd2
FROM Prod 
GROUP BY Prod.PruID;

Query 2: Summarize last 12 month of Prod1 & Prod2 by PruID

SELECT PruID, Sum(Prod1) AS Cum12MonProd1, Sum(Prod2) AS Cum12MonProd2
FROM Prod
WHERE Prod.ReportDate > DATEADD('m', -12, now())
GROUP BY PruID;

How to combine the 2 queries to one to produce something like this:

PruID  CumProd1 CumProd2 Cum12MonProd1 Cum12MonProd2

Answer 1

The trick here is to exclude the data that you're filtering out in the second query from the sum function for the filtered total.

SELECT   prod.pruid,
         SUM (prod.prod1) AS cumprod1,
         SUM (prod.prod2) AS cumprod2,
         SUM (
            CASE
               WHEN prod.reportdate > dateadd ('m', -12, now ()) THEN
                  prod.prod1
               ELSE
                  NULL
            END)
            AS cum12monprod1,
         SUM (
            CASE
               WHEN prod.reportdate > dateadd ('m', -12, now ()) THEN
                  prod.prod2
               ELSE
                  NULL
            END)
            AS cum12monprod2
FROM     prod
GROUP BY prod.pruid;

Answer 2

You could either JOIN the two subqueries:

SELECT a.PurID, a.CumProd1, a.CumProd2, b.Cum12MonProd1, b.Cum12MonProd2
FROM
(

    SELECT Prod.PruID, Sum(Prod.Prod1) AS CumProd1, Sum(Prod.Prod2) AS CumProd2
    FROM Prod 
    GROUP BY Prod.PruID
) a INNER JOIN
(

    SELECT PruID, Sum(Prod1) AS Cum12MonProd1, Sum(Prod2) AS Cum12MonProd2
    FROM Prod
    WHERE Prod.ReportDate > DATEADD('m', -12, now())
    GROUP BY PruID
) b
ON a.PruID = b.PruID;

or use a CASE in the second set of sums:

SELECT 
    Prod.PruID, 
    Sum(Prod.Prod1) AS CumProd1, 
    Sum(Prod.Prod2) AS CumProd2,
    Sum(CASE WHEN Prod.ReportDate > DATEADD('m', -12, now()) THEN Prod1 ELSE 0) AS Cum12MonProd1,
    Sum(CASE WHEN Prod.ReportDate > DATEADD('m', -12, now()) THEN Prod2 ELSE 0) AS Cum12MonProd2
FROM Prod 
GROUP BY Prod.PruID;