A friend of me asked me long time ago: "How can I have a ranking on a result with MySQL?". Now I found some time to write it down:
Lets do first some preparation for the example:
CREATE TABLE sales (
id INT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY
, fruit VARCHAR(32)
, amount DECIMAL
);
INSERT INTO sales
VALUES (NULL, 'apple', 12.75), (NULL, 'orange', 1.89), (NULL, 'pear', 19.23)
, (NULL, 'banana', 4.25), (NULL, 'cherry', 123.75), (NULL, 'plum', 23.15)
;
Now lets query:
SELECT fruit, amount
FROM sales
ORDER BY amount DESC
;
+--------+--------+
| fruit | amount |
+--------+--------+
| cherry | 124 |
| plum | 23 |
| pear | 19 |
| apple | 13 |
| banana | 4 |
| orange | 2 |
+--------+--------+
Hmmmm...., this not yet what we want!
And now with ranking:
SET @rank=0;
SELECT @rank:=@rank+1 AS rank, fruit, amount
FROM sales
ORDER BY amount DESC
;
+------+--------+--------+
| rank | fruit | amount |
+------+--------+--------+
| 1 | cherry | 124 |
| 2 | plum | 23 |
| 3 | pear | 19 |
| 4 | apple | 13 |
| 5 | banana | 4 |
| 6 | orange | 2 |
+------+--------+--------+
Much better!
An other possibility would be, to do the whole ranking in the application (on the application server).
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