Question

We have a so called evaluation process for new products which is fairly complex. A product is evaluated for different Regions and applications. Afer each evalution step the product gets a new Result score. this score (between 0 to 10) says how far the product is in the process. For each step it stays the same or is increased but never decreased and uneven numbers mark products that failed the evaluation. The highest score is called the products Status.

I no want to Select all products that had an even status (2,4,8,10) at startDate (including that status) and the status at endDate of the time frame.

(I also want to select all new products that entered the proccess in that time frame but I think that can be done easly in a second statement.)

The issue I have is how to include both initial status in the output. Here is my SQL Statement:

SELECT 
  MyTable.product_id, 
  MyTable.REGION, 
  MyTable.SEGMENT,
  Max(MyTable.result) AS NEW_STATUS
  FROM 
     MyTable INNER JOIN (
     SELECT
      product_id, 
      REGION, 
      SEGMENT, 
      Max(result) AS INITIAL_STATUS
    FROM
      MyTable
    WHERE
      DATE <= to_date(:startDate)
    GROUP BY
      product_id, REGION, SEGMENT
    HAVING
      Max(result) IN(2,4,8,10)
   ) initial_status ON MyTable.product_id = initial_status.product_id    
  WHERE
    MyTable.DATE <= to_date(:endDate)
  GROUP BY
    MyTable.product_id, 
    MyTable.REGION, 
    MyTable.SEGMENT;

How can I include initial_status in the output without affecting max/group by?
(is oracle, but I’m no expert so maybe some oracle specific stuff can help)

EDIT:

the data is in a 1 to many relationship. 1 product, many evaluations. each evaluation has an Region, segment, result and evaluation_date (plus other data not relevant here). denormalized here some example data:

product_id    Region    Segment    Result    date
    1           US         AB         2    20.05.2012
    1           EU         TS         4    13.06.2012
    1           US         AB         4    01.09.2012
  234           US         AB         2    09.09.2012

Expected output for above sample with date Range from 26.08.2012 to 21.09.2012:

product_id    Region    Segment    Initial_Status    New_Status
    1            US        AB             2              4
    1            EU        TS             4              4 (this did not change)
  234            US        AB           (null)           2 ( new entry)

I know my current SQL can’t achieve that. especially displaying the values that are new.

Answer 1

Just for documentation I came up with following query. I know it contains certain requirements not asked in the initial question. Some of them are due to deal with faulty data.

SELECT 
  product_id, 
  REGION, 
  SEGMENT,
  initial_status,
  NEW_STATUS,
  "Comment",
  Count("Comment")  OVER (PARTITION BY 
      "Comment"
    ) "Counter"
from(
SELECT DISTINCT
  myTable.product_id, 
  myTable.REGION, 
  myTable.SEGMENT,
  initial_status.initial_status,
  Max(myTable.result) 
    OVER (PARTITION BY 
      myTable.product_id, 
      myTable.REGION, 
      myTable.SEGMENT
    ) NEW_STATUS,
  CASE WHEN initial_status.initial_status <> Max(myTable.result) 
    OVER (PARTITION BY 
      myTable.product_id, 
      myTable.REGION, 
      myTable.SEGMENT
    ) THEN 'Changed' ELSE 'Same' END as "Comment"  
  FROM 
    myTable INNER JOIN (
     SELECT
      product_id, 
      REGION, 
      SEGMENT, 
      Max(result) AS INITIAL_STATUS
    FROM
      myTable
    WHERE
      DATE <= to_date(:startDate)
      OR DATE is null
    GROUP BY
      product_id, REGION, SEGMENT
    HAVING
      Max(result) IN(2,4,8,10)
   ) initial_status 
    ON 
      myTable.product_id = initial_status.product_id
      AND myTable.REGION = initial_status.REGION
      AND (
        myTable.SEGMENT = initial_status.SEGMENT
        OR (myTable.SEGMENT is null AND initial_status.SEGMENT is null)
      )
  WHERE
    myTable.DATE <= to_date(:endDate)
UNION ALL
SELECT 
  myTable.product_id, 
  myTable.REGION, 
  myTable.SEGMENT,
  null AS initial_status,
  Max(myTable.result) 
    OVER (PARTITION BY 
      myTable.product_id, 
      myTable.REGION, 
      myTable.SEGMENT
    ) NEW_STATUS,
'New' As "Comment"
FROM myTable
WHERE evaluation_date BETWEEN to_date(:startDate) + 1 AND to_date(:endDate)
AND stage <> 'Stage 0')
ORDER BY
    product_id ASC;