If you would like to get purchased items which are not sold, use this query:
SELECT *
FROM Purchased_Items
WHERE NOT Item_ID IN (SELECT Item_ID FROM Sold_Items)
If you would like to sum Item_Quantity for both tables:
SELECT 'Sum Of Purchased_Items' As [Item Description], SUM(Item_Quantity) AS [Item Value]
FROM Purchased_tems
UNION ALL
SELECT 'Sum Of Sold_Items' As [Item Description], SUM(Item_Quantity) AS [Item Value]
FROM Purchased_tems
Example output:
Item Description | Item Value |
---|
Sum Of Purchased_Items | 5,000.00 |
Sum Of Sold_Items | 2,000.00 |