选择项目数在mysql

Question

I've a table like the following,

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

and i need the result somethin like,

id rating count
1 3 2
1 4 1
2 1 1

is it possible in mysql?

Answer 1

GROUP BY can be applied to multiple columns at once. Try:

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

Answer 2

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

您应该更多地标准化表格。

Answer 3

Query should be like this

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