mysql - count(*) 查询问题

Question

我有一个包含这些记录的表:

id         code        date
-----      ------      -----
1          12          2016-01-01
2          12          2016-01-02
3          17          2016-01-03
4          12          2016-01-04
5          17          2016-01-05
6          17          2016-01-06
7          17          2016-01-07

我使用这个查询:

SELECT `id`, `code`, `date`, COUNT(*) AS total 
FROM `foo` 
GROUP BY (code) 
ORDER BY (id) DESC

我明白了:

id         code        date           total
-----      ------      ------         ------
3          17          2016-01-03     4
1          12          2016-01-01     3

但我需要显示这个:

id         code        date           total
-----      ------      ------         ------
7          17          2016-01-07     4
4          12          2016-01-04     3

这可能吗？非常感谢。

Answer 1

使用MAX函数:

SQL Fiddle

SELECT
    MAX(id) AS id,
    code,
    MAX(date) AS date,
    COUNT(*) AS total
FROM foo
GROUP BY code
ORDER BY MAX(id) DESC;