mysql query grouping

I am making a shopping cart. Selected items are stored inside a database based on a search query.

How I can add the quantit开发者_如何学Pythony for rows in case sku, type and color are the same values?

example:

sku  type   color  quantity
---------------------------
1    type1  blue   5
1    type1  blue   2
2    type1  blue   5
1    type1  green  5

my new rows should be:

sku  type   color  quantity
---------------------------
1    type1  blue   7
2    type1  blue   5
1    type1  green  5

Notice the first row quantity is now 7.

How can this be done? I tried GROUP BY, but didn't know how to make it dynamic to match all.

  SELECT sku,type,color, 
         SUM(quantity) 
    FROM table 
GROUP BY sku,type,color

SELECT sku, type, color, sum(quantity)
FROM theTable
GROUP BY  sku, type, color

That will do it.

CREATE TEMPORARY TABLE IF NOT EXISTS tmpTable LIKE dataTable

DELETE FROM tmpTable

Insert into tmpTable
select sku,type,color,sum(quantity) from dataTable
group by sku,type,color

DELETE FROM dataTable

INSERT INTO dataTable
SELECT * FROM tmpTable