mysql - 仅获取每个代码的最近日期的记录

Question

我有一张这样的 table

+------+-------+-----------+-------------+
| code | price | perct_off | date_review |
+------+-------+-----------+-------------+
| 0001 |  1500 |        40 | 2017-12-30  |
| 0001 |  1500 |        40 | 2018-02-15  |
| 0001 |  2000 |        25 | 2018-07-31  |
| 0002 |  3000 |        45 | 2018-03-20  |
| 0002 |  5000 |        20 | 2018-08-01  |
| 0003 |  3000 |        40 | 2018-01-16  |
+------+-------+-----------+-------------+

我只想记录每个代码的最大日期。输入必须是:

+------+-------+-----------+-------------+
| code | price | perct_off | date_review |
+------+-------+-----------+-------------+
| 0001 |  2000 |        25 | 2018-07-31  |
| 0002 |  5000 |        20 | 2018-08-01  |
| 0003 |  3000 |        40 | 2018-01-16  |
+------+-------+-----------+-------------+

当我尝试时:

SELECT DISTINCT
    (code), price, perct_off, MAX(date_review)
FROM `table01`
GROUP BY code

我得到了这个输出

+-------+--------+------------+-------------------+
| code  | price  | perct_off  | max(date_review)  |
+-------+--------+------------+-------------------+
| 0001  |   1500 |         40 | 2018-07-31        |
| 0002  |   3000 |         45 | 2018-08-01        |
| 0003  |   3000 |         40 | 2018-01-16        |
+-------+--------+------------+-------------------+ 

如何获得正确的输出？

提前致谢。

Answer 1

执行此操作的一种规范方法是加入子查询，该查询为每个 code 查找最近的日期:

SELECT t1.*
FROM table01 t1
INNER JOIN
(
    SELECT code, MAX(date_review) AS max_date_review
    FROM table01
    GROUP BY code
) t2
    ON t1.code = t2.code AND t1.date_review = t2.max_date_review;