How to sum values in MySQL query

Question

I know how to count total results:

SELECT COUNT(*) as Count FROM store_items

This will give me the total number of unique items in my store. However, some items may have more than 1 quantity. The table is like:

ID    Sku   Qty
1     500   3
2     501   1
3     502   6

How do I modify the query to return 10 instead of 3 (counting the values in all the Qty fields)?

Answer 1

You should group them:

SELECT SUM(`Qty`) as `Quantity` 
FROM `store_items`
GROUP BY `Sku`

This way you get sums for each Sku you have. So if you have multiple rows of each Sku, they would all be summed.

Answer 2

SELECT SUM(Qty) AS sum FROM store_items