mysql - 在mysql中选择项目计数

Question

我有一张如下表，

id ip等级
1 192.161.0.1 3
1 192.161.0.2 4
1 192.161.0.4 3
2 192.161.0.5 1

我需要类似的结果，

id 评分计数
1 3 2
1 4 1
2 1 1

在mysql中可以吗？

Answer 1

查询应该是这样的

SELECT id, rating, COUNT(rating) AS count
FROM yourtable
GROUP BY  id,rating
ORDER BY id, rating

Answer 2

GROUP BY可以一次应用于多个列。尝试：

SELECT id, rating, COUNT(id) AS count
FROM yourtable
GROUP BY id, rating
ORDER BY id, rating

Answer 3

SELECT `id`, `rating`, COUNT(`id`) AS `count` FROM `table` GROUP BY `id`, `rating`.

你应该更多地规范你的表。