Oracle, SQL Conditional exclusion based on the items in the joined table - sql

Question

The following query excludes all the products however, I am trying to exclude the products "only if" the R.OPERATING_UNITS = 'WP' and PRODUCT_CAT = 'FUEL' in the joined table. I don't know how to condition that. I wanted to know what is the best efficient way to do that. Below is the query, the RESOURCE, PRODUCT table and also the desired result set. I simplified both the tables and query for the sake of explanation.
SELECT R.DEPTID,
R.FISCAL_YEAR,
sum(R.AMOUNT) total
FROM RESOURCE R
WHERE
R.PRODUCT_ID NOT IN (
SELECT PRODUCT_ID FROM PRODUCT WHERE PRODUCT_CAT='FUEL' )
group by R.FISCAL_YEAR,R.DEPTID
the RESOURCE table
DPTID FISCAL_YEAR OPERATING_UNIT AMOUNT PRODUCT
PTT 2017 WP 1200 31000
PTT 2017 SP 3000 32000
PTT 2017 GP 1000 31000
PTT 2017 WP 1000 32000
FPP 2017 WP 1000 32000
FPP 2018 GP 2000 33000
FPP 2017 SP 1000 32000
FPP 2018 WP 2200 31000
PRODUCT Table:
PRODUCT PRODUCT_CAT
31000 FUEL
32000 NON-FUEL
33000 MATERIAL
Result set. Note that it is ignoring WP when calculating the sum.
2017 PTT 5000 (igonred 1200 since operating unit=wp and product is 31000->FUEL but included wp and 32000)
2017 FPP 2000
2018 FPP 2000 (it did not consider the 2200 since operating unit=wp and product is 31000->FUEL)

Answer 1

WP filter should work after you change below statement
NOT IN (
SELECT PRODUCT_ID FROM PRODUCT WHERE PRODUCT_CAT='FUEL' )
and then you can filter operating unit.
SELECT R.DEPTID,
R.FISCAL_YEAR,
sum(R.AMOUNT) total
FROM RESOURCE R
WHERE
r.OPERATING_UNIT = 'WG' and
R.PRODUCT_ID IN
(
SELECT PRODUCT_ID FROM PRODUCT WHERE PRODUCT_CAT='FUEL' )
group by R.FISCAL_YEAR,R.DEPTID

Answer 2

Sticking in a not-equal to clause with an OR in-between should filter out the cases where both OperatingUnit = 'WP' & ProductCat = 'Fuel'
SELECT r.DEPTID
,r.FISCAL_YEAR
,SUM(r.AMOUNT) AS TOTAL
FROM [Resource] r
INNER JOIN [Product] p ON r.PRODUCT = p.PRODUCT
WHERE r.OPERATING_UNIT != 'WP'
OR p.PRODUCT_CAT != 'FUEL'
GROUP BY r.DEPTID
,r.FISCAL_YEAR
I used the following query below to view the data and verify that it's returning the 6/8 rows I wanted.
SELECT *
FROM [Resource] r
INNER JOIN [Product] p ON r.PRODUCT = p.PRODUCT

Answer 3

For ease of writing - and reading - the exclusion condition, it would be nice if we could work with tuples. And we can. One benefit is that it will be easy, in the future, to add other pairs of operating unit and product category to the exclusion list, without having to write lengthy conditions with lots of OR and AND.
If you run a query like this, and then you take a look at the EXPLAIN PLAN for the query, you will see that the parser expanded the tuple condition to a long logical expression with OR (and AND, if more than one tuple is excluded) - so the end result is the same, but the code looks more natural.
select r.deptid, r.fiscal_year, sum(r.amount) as total
from resource r inner join product p on r.product = p.product
where (r.operating_unit, p.product_cat) not in ( ('WP', 'FUEL') )
group by r.deptid, r.fiscal_year
;
Regarding NULL: if either r.operating_unit or p.product_cat can be NULL, you need to state how they should be handled. If, for example, the operating unit is WP but the product category is NULL, the corresponding row will be excluded in the query above. That may be the proper handling: the unit is definitely 'WP', and since we don't know the product category, we must make a decision. Since it may be 'FUEL', we just don't know for sure, we may choose to exclude it. Obviously, if both columns are NOT NULL then this is not an issue.
Note - I hope you don't really have a table PRODUCT with a column PRODUCT; that will lead to confusion which almost always then leads to bugs.