Fetch only matching records from two entities - mysql

Question

Please help me with the MYSQL query.
Entity Name: OrderItem
Attributes: orderId(PK), orderItemSeqId(PK), productId
Entity Name: ProductFacility
Attributes: facilityId(PK), productId(PK), inventoryCount (Integer)
**OrderId | orderItemSeqId | productId**
OID1 | 0001 | 10000
OID1 | 0002 | 10001
OID1 | 0003 | 10002
**FacilityId | ProductId | InventoryCount**
FC_1 | 10000 | 12
FC_1 | 10001 | 5
FC_1 | 10002 | 7
FC_2 | 10001 | 1
FC_2 | 10002 | 6
FC_3 | 10002 | 7
Here I want to fetch the facility (FC_1) which has all the products available for order.
I don't want the facility records which has partial products (like facility FC_3 has only one (10002) product from order OID1)
I only want the facilityId records which have all the products from the order (ex OID1)
IMPORTANT POINT: This SQL will be executed on millions of records.

Answer 1

Try this:
select *
from ProductFacility f1
where (select count(distinct InventoryCount) cnt_fac
from ProductFacility f2
where f2.FacilityId = f1.FacilityId
and InventoryCount > 0
group by FacilityId ) = (select count(distinct productId)
from OrderItem );
Here is a DEMO

Answer 2

This will get you the facilities you are looking for
with cte as
(
select OrderId, count(*) as c
from orderT a
group by OrderId
)
select FacilityId, b.OrderId, count(*) as c from Facility a
inner join orderT b on a.ProductId = b.ProductId
group by FacilityId, b.OrderId
having count(*) = (select c from cte c where c.OrderId = b.OrderId)

Answer 3

To get a list of which facilities can satisfy an order, you need to check which facility has InventoryCount > 0 for each product in the order, which you can do with this query:
SELECT O.OrderId, F.FacilityID
FROM (SELECT DISTINCT productId
FROM OrderItem) P
CROSS JOIN (SELECT DISTINCT OrderId
FROM OrderItem) O
CROSS JOIN (SELECT DISTINCT FacilityId
FROM ProductFacility) F
LEFT JOIN OrderItem OI ON OI.OrderId = O.OrderID AND OI.productId = P.productId
LEFT JOIN ProductFacility PF ON PF.FacilityId = F.FacilityId AND PF.productId = OI.productId AND PF.InventoryCount > 0
GROUP BY O.OrderId, F.FacilityID
HAVING COUNT(OI.ProductId) = COUNT(PF.ProductId)
I have added an additional order to my demo which requires products 10001 and 10002; for that the output is
OrderId FacilityID
OID1 FC_1
OID2 FC_1
OID2 FC_2
Demo on SQLFiddle

Answer 4

This should work:
select oc.orderId, ofc.facilityId
from
(
select orderId, count(*) productCount
from OrderItem
group by orderId) oc
inner join
(
select pf.facilityId, oi.orderId, count(*) productsAvailableCount
from ProductFacility pf
inner join OrderItem oi on oi.productId = pf.productId and pf.inventoryCount > 0
group by pf.facilityId, oi.orderId
) ofc on ofc.orderId = oc.orderId and oc.productCount = ofc.productsAvailableCount
Demo on DB Fiddle