Nested CASE in SQL - sql

Question

TABLE1:
ARTIKEL SUPPLIERID SALE_SUM_PIECES
TV SONY 7
TABLE2:
ROW_ID ARTIKEL SUPPLIERID PIECES
1 TV SONY 6
2 TV SONY 10
3 TV SONY 6
4 TV SONY 14
5 TV SONY 18
6 TV SONY 4
I need to subtract value X=23 on TABLE2."PIECES", only when the value TABLE1."SALE_SUM_PIECES" is less than the SUM of "PIECES" in TABLE2. For example: the value of TABLE1."SALE_SUM_PIECES" is 7. NOw I need to check at which row the value 7 goes less than the SUM of TABLE2."PIECES".In the below example the first row in TABLE2 is not valid because 7 is greater than 6. But the second row in TABLE2 is valid since the SUM OF "PIECES" from row1 and row2 in TABLE2 i.e 6+10=16 is greater than 7. So, I need to subtract value of X=23 from the second row to the following rows in TABLE2.
The query I have is as follows:
SELECT "SUPPLIERID", "ARTIKEL",
(case when ( cumulativesum - (select "SALE_SUM_PIECES" from T1 where T1."SUPPLIERID"=T2."SUPPLIERID" and T1."ARTIKEL" = T2."ARTIKEL" )) <= 0
then NULL
when ( cumulativesum - (select "SALE_SUM_PIECES" from TABLE1 T1 where T1."SUPPLIERID"=T2."SUPPLIERID" and T1."ARTIKEL" = T2."ARTIKEL" )) > 0
then
(case when #x - cumulativesum <= 0 and #x - (cumulativesum -PIECES) > 0
then 0
when #x - "cumulativesum" <= 0
then NULL
else #x - "cumulativesum"
end) as "VALUE_DRILL_DOWN"
from (SELECT T1."ARTIKEL", T1."SUPPLIERID", T1.PIECES
(select sum("PIECES")
from EXAMPLE_TABLE T2
where T2."ROW_ID" <= T1."ROW_ID" and T2."SUPPLIERID" = T1."SUPPLIERID" and T2."ARTIKEL"=T1."ARTIKEL"
) as "cumulativesum"
from EXAMPLE_TABLE T1
)
When I execute the above query I get the result as follows:
ROW_ID ARTIKEL SUPPLIERID PIECES VALUE_DRILL_DOWN
1 TV SONY 6 NULL
2 TV SONY 10 7
3 TV SONY 6 1
4 TV SONY 14 0
5 TV SONY 18 Null
6 TV SONY 4 Null
But I expect a result to be as follows:
ROW_ID ARTIKEL SUPPLIERID PIECES VALUE_DRILL_DOWN
1 TV SONY 6 NULL
2 TV SONY 10 13
3 TV SONY 6 7
4 TV SONY 14 0
5 TV SONY 18 Null
6 TV SONY 4 Null
I want the subtraction of ´X=23´ to start from the row in TABLE2 where the condition TABLE1."SALE_SUM_PIECES" < TABLE2."PIECES" i.e from row2. Any suggestions?
Thanks in advance.

Answer 1

The below solution gives the desired results. See SqlFiddle
1 TV SONY 922 6 110 2.50 NULL
2 TV SONY 922 10 80 1.00 13
3 TV SONY 922 6 65 1.50 7
4 TV SONY 922 14 95 1.50 0
5 TV SONY 922 18 95 1.50 NULL
6 TV SONY 922 4 95 1.50 NULL
DECLARE #x INT = 23
; WITH cte AS
(
SELECT t2.*, t1.SALE_SUM_PIECES,
CASE
WHEN SUM(t2.PIECES) OVER (PARTITION BY t2.ARTIKEL, t2.SUPPLIERID ORDER BY ROW_ID) < t1.SALE_SUM_PIECES THEN 'None'
ELSE t2.ARTIKEL + t2.SUPPLIERID
END AS GroupId
FROM #Table2 t2
JOIN #Table1 t1 ON t2.ARTIKEL = t1.ARTIKEL AND t2.SUPPLIERID = t1.SUPPLIERID
),
cumulative AS
(
SELECT *, SUM(PIECES) OVER (PARTITION BY GroupId ORDER BY ROW_ID) AS CumulativeSum
FROM cte
)
SELECT ROW_ID, ARTIKEL, SUPPLIERID, ORGID, PIECES, COSTPRICE, DISCOUNT,
CASE
WHEN CumulativeSum < SALE_SUM_PIECES THEN NULL
WHEN #x - CumulativeSum <= 0 AND #x - (CumulativeSum - PIECES) > 0 THEN 0
WHEN #x - CumulativeSum <= 0 THEN NULL
ELSE #x - CumulativeSum
END AS VALUE_DRILL_DOWN
FROM cumulative

Answer 2

I'm not 100% sure what the expected calulation for VALUE_DRILL_DOWN is supposed to be.
You've said that for a valid row, it should be (sum of all rows at or above row) - 23
In this case the following code should work, but it gives different numbers from your expected results.
I've used a self-joining common table expression to work out the cumulative sums of the rows as you count up .
The (total of all rows at or above) is equal to the (total) - (cumulative sum at row before)
Therefore the following code should be correct...
DECLARE #table1 TABLE(ARTIKEL NVARCHAR(50), SUPPLIERID NVARCHAR(50), ORGID INT,
STORE INT, SALE_SUM_PIECES INT, [DATE] DATETIME)
DECLARE #table2 TABLE(ROW_ID INT, ARTIKEL NVARCHAR(50), SUPPLIERID NVARCHAR(50),
ORGID INT, PIECES INT, COSTPRICE MONEY, DISCOUNT DECIMAL(9,5))
DECLARE #x INT = 23
DECLARE #SumOfAll INT
INSERT #table1
( ARTIKEL , SUPPLIERID , ORGID , STORE , SALE_SUM_PIECES , [DATE] )
VALUES ( 'TV', 'SONY', 922,100,7 ,'2014-01-01' )
INSERT #table2
(ROW_ID, ARTIKEL , SUPPLIERID , ORGID , PIECES , COSTPRICE , DISCOUNT )
VALUES (1, 'TV', 'SONY', 922, 6, 110, 2.5 ),
(2, 'TV', 'SONY', 922, 10 , 80, 1 ) ,
(3, 'TV', 'SONY', 922, 6 , 65 , 1.5 ) ,
(4, 'TV', 'SONY', 922, 14 , 95 , 1.5 ),
(5, 'TV', 'SONY', 922, 18 , 95 , 1.5 ),
(6, 'TV', 'SONY', 922, 4 , 95 , 1.5 )
SELECT #SumOfAll = SUM(PIECES) FROM #table2 AS t
;WITH t2C AS (
SELECT ROW_ID, PIECES AS [cumulativeSum]
FROM #table2 AS t
WHERE ROW_ID = 1 -- assume starting at 1
UNION ALL
SELECT t.ROW_ID, t.PIECES + cumulativeSum AS [cumlativeSum]
FROM #table2 AS t
JOIN t2C ON t2C.ROW_ID + 1 = t.ROW_ID --assume rowIDs are sequential
)
SELECT
t2.ROW_ID,
t1.SUPPLIERID,
t1.ORGID,
t2.PIECES,
t2.COSTPRICE,
t2.DISCOUNT,
CASE WHEN t2C.cumulativeSum - t1.SALE_SUM_PIECES <= 0 THEN NULL
ELSE
CASE
WHEN #x - t2C.cumulativeSum <= 0
AND #x - (t2C.cumulativeSum - t2.PIECES) > 0 THEN 0
WHEN #x - t2C.cumulativeSum <= 0 THEN NULL
ELSE (#SumOfAll - t2cPrev.cumulativeSum) - #x
END
END AS [VALUE_DRILL_DOWN]
FROM t2C
LEFT JOIN t2C AS t2cPrev ON t2cPrev.ROW_ID = t2C.ROW_ID - 1
JOIN #table2 AS t2 ON t2.ROW_ID = t2C.ROW_ID
JOIN #table1 AS t1 ON t1.SUPPLIERID = t2.SUPPLIERID AND t1.ARTIKEL = t2.ARTIKEL
However this gives:
ROW_ID SUPPLIERID ORGID PIECES COSTPRICE DISCOUNT VALUE_DRILL_DOWN cumulativeSum sumOfRowsOnOrAfter
1 SONY 922 6 110.00 2.50000 NULL 6 NULL
2 SONY 922 10 80.00 1.00000 29 16 52
3 SONY 922 6 65.00 1.50000 19 22 42
4 SONY 922 14 95.00 1.50000 0 36 36
5 SONY 922 18 95.00 1.50000 NULL 54 22
6 SONY 922 4 95.00 1.50000 NULL 58 4
EDIT:
SQL Fiddle by WiiMaxx

Answer 3

select
*,
case when 23 - sum(c) over (order by row_id) >= 0
then 23 - sum(c) over (order by row_id)
when 23 - sum(c) over (order by row_id) + pieces > 0
then 0
end value_drill_down
from (
select *,
case when sum(pieces) over (order by row_id) >= (select sale_sum_pieces from t1)
then pieces
end c
from t2) x;