SQL - Group by issues

I have this table that looks like this

CREATE TABLE `purchases` (
    `id` INT(10) NOT NULL AUTO_INCREMENT,
    `totalAmount` INT(10) NOT NULL DEFAULT '0',
    `storeId` INT(10) NOT NULL DEFAULT '0',
    `purchaseDate` DATETIME NOT NULL,
    PRIMARY KEY (`id`)
)

I want to count all the purchases on a given day so I have this SQL statement that does that

SELECT DATE_FORMAT(purchaseDate, '%m-%d-%Y') AS date, COUNT(id) AS totalPurchases FROM purchases GROUP BY DATE(purchaseDate)

That returns me something like this

date        totalPurchases
11-18-2010  5
11-19-2010  10
11-20-2010  10

Since each purchase is tied to a store, I was wondering if there is a query that will add 3 columns to that resultset with a count of purchases that happened in each store to give me something like this

date        totalPurchases     store1    store2    store3
11-18-2010  5     开发者_JAVA技巧             2         1         2
11-19-2010  10                 4         1         5
11-20-2010  10                 3         4         3

Thanks in advance!

---

  SELECT DATE_FORMAT(purchaseDate, '%m-%d-%Y') AS date,
         COUNT(*) AS totalPurchases,
         SUM(IF(storeId = 1, 1, 0)) AS store1,
         SUM(IF(storeId = 2, 1, 0)) AS store2,
         SUM(IF(storeId = 3, 1, 0)) AS store3
    FROM purchases
GROUP BY DATE(purchaseDate)

---

Perhaps you could use ROLLUP for this, check out the documentation here