如何使用MySQL获取最新日期

Question

如何使用MySQL获取最新日期？ 我试过最大但我没有得到我想要的结果。 我的表看起来像这样：

+---------+---------+-----------------------+--------+------------+---------+
| Name    | idStore | Name                  | idItem | date       | price   |
+---------+---------+-----------------------+--------+------------+---------+
| walmart |       1 | Red Delicious Apples  |      1 | 2011-10-22 | 0.98000 |
| walmart |       1 | Red Delicious Apples  |      1 | 2011-10-28 | 0.98000 |
| walmart |       1 | Red Delicious Apples  |      1 | 2011-10-28 | 0.98000 |
| walmart |       1 | Red Delicious Apples  |      1 | 2011-11-22 | 0.98000 |
| walmart |       1 | Honeycrisp Apples     |      2 | 2011-10-22 | 1.98000 |
| walmart |       1 | Sonya Apples          |      3 | 2011-10-22 | 2.88000 |
| walmart |       1 | Gold Delicious Apples |      4 | 2011-10-22 | 0.98000 |
| walmart |       1 | Sweet Tango Apples    |      5 | 2011-10-22 | 2.48000 |
| walmart |       1 | Granny Smith Apples   |      6 | 2011-10-22 | 1.28000 |
| walmart |       1 | Fugi Apples           |      7 | 2011-10-22 | 1.38000 |
+---------+---------+-----------------------+--------+------------+---------+

我想得到这张桌子：

+---------+---------+-----------------------+--------+------------+---------+
| Name    | idStore | Name                  | idItem | date       | price   |
+---------+---------+-----------------------+--------+------------+---------+
| walmart |       1 | Red Delicious Apples  |      1 | 2011-11-22 | 0.98000 |
| walmart |       1 | Honeycrisp Apples     |      2 | 2011-10-22 | 1.98000 |
| walmart |       1 | Sonya Apples          |      3 | 2011-10-22 | 2.88000 |
| walmart |       1 | Gold Delicious Apples |      4 | 2011-10-22 | 0.98000 |
| walmart |       1 | Sweet Tango Apples    |      5 | 2011-10-22 | 2.48000 |
| walmart |       1 | Granny Smith Apples   |      6 | 2011-10-22 | 1.28000 |
| walmart |       1 | Fugi Apples           |      7 | 2011-10-22 | 1.38000 |
+---------+---------+-----------------------+--------+------------+---------+

我很难搞清楚这一点。 谢谢！

Answer 1

您可以使用group by：

select NameStore, idStore, Name, idItem, max(date) date, price
from table
group by NameStore, idStore, Name, idItem, price

Answer 2

在线示例查询

http://data.stackexchange.com/stackoverflow/q/118881/how-can-i-get-the-most-resent-date-using-mysql

SELECT NameStore, idStore, Name, idItem, max(date) AS date, price
FROM tablename
GROUP by NameStore, idStore, Name, idItem, price
ORDER BY date DESC, idItem ASC

Answer 3

请参见SQL仅选择列上具有“最大值”的行

SELECT yt1.*
FROM yourtable yt1
LEFT OUTER JOIN yourtable yt2 ON (yt1.idItem = yt2.idItem AND yt1.date < yt2.date)
WHERE yt2.idItem IS NULL;

Answer 4

把它放在最后的ORDER BY date DESC

所以让它看起来像这样：

SELECT * FROM `tablename` ORDER BY `date` DESC

在上面的SQL语句中使用DISTINCT(Name)或GROUP BY Name ，只会使一个项目弹出一次。

Answer 5

你必须像这样使用GROUP BY子句：

SELECT Name, idStore, Name, idItem, date, price 
FROM mytable 
GROUP BY idItem 
ORDER BY date DESC, idItem DESC;

使用DESC或ASC更改订单方向。 您可以通过阅读文档了解更多信息。