Using multiple columns to determine SUM results - sql

Question

I am having trouble getting my head around the following sum. I have a table of items, which shows the location, the item code and the size code. The unique feature of this table is there is a flag that determines whether the location will stock a particular item.
I have another table that shows the stock movements of the items. This table also shows location, item, size and either a positive or negative entry. The sum of the positive/negative entries give the current stock holding.
What i can't seem to do is say SUM the stock movement quantities where the item and size are marked with 'location can stock this item'
The first select statement brings back items that can be stocked by location
select
S.[Location Code],S.[Item No_],S.[size],
from [Stockkeeping Units] S
where [Range in Location] = 1
The results return a list as:
location Code| Item no | Size
1 | SHIRT1 | s
1 | SHIRT1 | m
1 | SHIRT2 | s
1 | SHIRT2 | m
2 | SHIRT1 | s
2 | SHIRT2 | m
The second select statement bring back the current stock for an item by location
select
L.[Location Code],L.[Item No_],L.[size],
sum(L.[Quantity]) as Quantity
from [Item Ledger Entry] L
location Code| Item no | Size | Quantity
1 | SHIRT1 | s | 5
1 | SHIRT1 | m | 3
1 | SHIRT2 | s | 5
1 | SHIRT2 | m | 7
2 | SHIRT1 | s | 3
2 | SHIRT2 | m | 0
It is when i try to join these tables to bring back the combination of the first 2 select statements, that it goes astray
select L.[Location Code],L.[Item No_], L.[Variant Code],
sum(L.[Quantity]) as Quantity
from [$Item Ledger Entry] L
join [Stockkeeping Unit] on [Item Ledger Entry].[Item No] = [Stockkeeping
Unit].[Item No_]
where [Stockkeeping Unit].[Range in Location] = 1
group by L.[Location Code],L.[Item No_],L.[Variant Code]
What i would like to see is:
location|item no|size|quantity where range in location is yes
The joined query is bringing back result the are ignoring the
[Stockkeeping Unit].[Range in Location] = 1 request
The joined query is also not returning the same SUM results as the second SELECT query

Answer 1

It looks like you meant this:
SELECT [Location Code], [Item No_], [size], SUM([Quantity]) AS Quantity
FROM [Item Ledger Entry] L
WHERE EXISTS (
SELECT *
FROM [Stockkeeping Units] S
WHERE S.[Range in Location]=1
AND S.[Location code]=L.[Location code]
AND S.[Item No]=L.[Item no]
AND S.[Size]=L.[Size]
)
GROUP BY L.[Location Code], L.[Item No_], L.[size];