Calculating stock quantity from multiple table transactions with SQL - sql

Question

We had an issue with our stock whereby we had a balance column that would be added to or subtracted from whenever a transaction occurred.
There were some issues that we could not trace and hence have made changes whereby the stock would be calculated by adding and subtracting (where appropriate) the quantity moving and come up to today's stock value.
However now, the structure is such that one product has multiple stocks therefore product A with expiry 01/2012, 02/2013 etc.
I have currently created a query whereby for one stock of a product, it would calculate its current stock as follows:
select
(select ISNULL(sum(gd.qty),0) as grnadd from grns as g
INNER JOIN grndetails as gd ON g.id = gd.grnid
INNER JOIN stocks as s ON s.id = gd.stockid
where g.locationid = 10 and s.prodid =2653)
-
(select ISNULL(sum(cod.qty), 0) as salesub from salesorders as co
INNER JOIN salesorddetails as cod ON co.id = cod.cusordid
INNER JOIN stocks as s ON s.id = cod.stockid
where co.status != 'cancel' and co.locid = 10 and s.prodid =2653)
-
(select ISNULL(sum(cod.qty), 0) as cussub from customerorders as co
INNER JOIN customerorddetails as cod ON co.id = cod.cusordid
INNER JOIN stocks as s ON s.id = cod.stockid
where co.status != 'cancel' and co.locid = 10 and s.prodid =2653)
Therefore in this case the stock is calculated for one product however can I make a query that would list all products with their totals (as above) in the second column?
Thank you and hope the structure is understood from the above query
EDIT:
Stocks Table: id, prodid, expiry
Products Table: id, tradename
GRN Details Table: id, grnid, qty, stockid (since its affecting the stock not product)
Sales & Customer Order Details Table: id, cusordid, qty, stockid
GRN & Sales & Cus Ord Table: id, locid
Locations Table: id, locname

Answer 1

try to include all product-ids and group by it. here's some proposed code
select prodid, sum(total) as total from (
(select s.prodid
, ISNULL(sum(gd.qty),0) as total
from grns as g
INNER JOIN grndetails as gd
ON g.id = gd.grnid
INNER JOIN stocks as s
ON s.id = gd.stockid
where g.locationid = 10 group by s.prodid)
union all
(select s.prodid
, ISNULL(sum(cod.qty), 0)*(-1) as total
from salesorders as co
INNER JOIN salesorddetails as cod
ON co.id = cod.cusordid
INNER JOIN stocks as s
ON s.id = cod.stockid
where co.status != 'cancel'
and co.locid = 10 group by s.prodid)
union all
(select s.prod_id
, ISNULL(sum(cod.qty), 0)*(-1) as total
from customerorders as co
INNER JOIN customerorddetails as cod
ON co.id = cod.cusordid
INNER JOIN stocks as s
ON s.id = cod.stockid
where co.status != 'cancel'
and co.locid = 10 group by s.prodid)
) as x
group by prodid
i have changed all the minuses to union-alls so that the product-ids will not get subtracted from each other and the grand total will be calculated respective to your product-ids.

Answer 2

Try this:
WITH
S AS (
SELECT DISTINCT prodid FROM stocks
),
L AS (
/* SELECT 10 AS locationid */
SELECT DISTINCT locationid FROM grns
),
T1 AS (
select
g.locationid,
s.prodid,
sum(gd.qty) as grnadd
from grns as g
INNER JOIN grndetails as gd ON g.id = gd.grnid
INNER JOIN stocks as s ON s.id = gd.stockid
GROUP BY g.locationid, s.prodid
),
T2 AS (
select
co.locid as locationid,
s.prodid,
sum(cod.qty) as salesub
from salesorders as co
INNER JOIN salesorddetails as cod ON co.id = cod.cusordid
INNER JOIN stocks as s ON s.id = cod.stockid
where co.status != 'cancel'
GROUP BY co.locid, s.prodid
),
T3 AS (
select
co.locid as locationid,
s.prodid,
sum(cod.qty) as cussub
from customerorders as co
INNER JOIN customerorddetails as cod ON co.id = cod.cusordid
INNER JOIN stocks as s ON s.id = cod.stockid
where co.status != 'cancel'
GROUP BY co.locid, s.prodid
)
SELECT
S.prodid, L.locationid, ISNULL(grnadd, 0) - ISNULL(salesub, 0) - ISNULL(cussub, 0)
FROM
S CROSS JOIN
L LEFT OUTER JOIN
T1 ON T1.locationid = L.locationid AND T1.prodid = S.prodid LEFT OUTER JOIN
T2 ON T2.locationid = L.locationid AND T2.prodid = S.prodid LEFT OUTER JOIN
T3 ON T3.locationid = L.locationid AND T3.prodid = S.prodid
I assumed that location might be also important, so it returns 3 columns. If you want results only for location with id 10, then in L CTL uncomment first line and comment second.

Answer 3

assuming lots about your data model (hopefully i understood the question right), a group by might be the answer:
select
(select s.prodid, ISNULL(sum(gd.qty),0) as grnadd from grns as g
INNER JOIN grndetails as gd ON g.id = gd.grnid
INNER JOIN stocks as s ON s.id = gd.stockid
where g.locationid = 10
GROUP BY s.prodid)
-
(select s.prodid, ISNULL(sum(cod.qty), 0) as salesub from salesorders as co
INNER JOIN salesorddetails as cod ON co.id = cod.cusordid
INNER JOIN stocks as s ON s.id = cod.stockid
where co.status != 'cancel' and co.locid = 10
GROUP BY s.prodid)
-
(select s.prodid, ISNULL(sum(cod.qty), 0) as cussub from customerorders as co
INNER JOIN customerorddetails as cod ON co.id = cod.cusordid
INNER JOIN stocks as s ON s.id = cod.stockid
where co.status != 'cancel' and co.locid = 10
GROUP BY s.prodid)