SQL ORDER BY

ORDER BY 关键字用于对结果集进行排序。

SQL ORDER BY 关键字

ORDER BY 关键字用于对结果集按照一个列或者多个列进行排序。

ORDER BY 关键字默认按照升序对记录进行排序。如果需要按照降序对记录进行排序,您可以使用 DESC 关键字。

SQL ORDER BY 语法

SELECT column_name,column_name
FROM table_name
ORDER BY column_name,column_name ASC|DESC;

演示数据库

在本教程中,我们将使用 Web3 样本数据库。

下面是选自 "Websites" 表的数据:

+----+--------------+---------------------------+-------+---------+
| id | name         | url                       | alexa | country |
+----+--------------+---------------------------+-------+---------+
| 1  | Google       | https://www.google.cm/    | 1     | USA     |
| 2  | 淘宝          | https://www.taobao.com/   | 13    | CN      |
| 3  | 芝麻教程      | http://www.web3.xin/    | 4689  | CN      |
| 4  | 微博          | http://weibo.com/         | 20    | CN      |
| 5  | Facebook     | https://www.facebook.com/ | 3     | USA     |
+----+--------------+---------------------------+-------+---------+

ORDER BY 实例

下面的 SQL 语句从 "Websites" 表中选取所有网站,并按照 "alexa" 列排序:

实例

SELECT * FROM Websites
ORDER BY alexa;
执行输出结果:
mysql> select * from websites group by alexa;
+----+----------+---------------------------+-------+---------+
| id | name     | url                       | alexa | country |
+----+----------+---------------------------+-------+---------+
|  1 | Google   | https://www.google.cm/    | 1     | USA     |
|  2 | 淘宝     | https://www.taobao.com/   | 13    | CN      |
|  4 | 微博     | http://weibo.com/         | 20    | CN      |
|  5 | Facebook | https://www.facebook.com/ | 3     | USA     |
|  3 | 芝麻教程 | http://www.web3.xin/      | 689   | CN      |
+----+----------+---------------------------+-------+---------+
5 rows in set (0.01 sec)
ORDER BY DESC 实例

下面的 SQL 语句从 "Websites" 表中选取所有网站,并按照 "alexa" 列降序排序:

实例

SELECT * FROM Websites
ORDER BY alexa DESC;
执行输出结果:
mysql> select * from websites group by alexa desc;
+----+----------+---------------------------+-------+---------+
| id | name     | url                       | alexa | country |
+----+----------+---------------------------+-------+---------+
|  3 | 芝麻教程 | http://www.web3.xin/      | 689   | CN      |
|  5 | Facebook | https://www.facebook.com/ | 3     | USA     |
|  4 | 微博     | http://weibo.com/         | 20    | CN      |
|  2 | 淘宝     | https://www.taobao.com/   | 13    | CN      |
|  1 | Google   | https://www.google.cm/    | 1     | USA     |
+----+----------+---------------------------+-------+---------+
5 rows in set (0.01 sec)

ORDER BY 多列

下面的 SQL 语句从 "Websites" 表中选取所有网站,并按照 "country" 和 "alexa" 列排序:

实例

SELECT * FROM Websites ORDER BY country,alexa;
执行输出结果:
mysql> select * from websites group by country,alexa;
+----+----------+---------------------------+-------+---------+
| id | name     | url                       | alexa | country |
+----+----------+---------------------------+-------+---------+
|  2 | 淘宝     | https://www.taobao.com/   | 13    | CN      |
|  4 | 微博     | http://weibo.com/         | 20    | CN      |
|  3 | 芝麻教程 | http://www.web3.xin/      | 689   | CN      |
|  1 | Google   | https://www.google.cm/    | 1     | USA     |
|  5 | Facebook | https://www.facebook.com/ | 3     | USA     |
+----+----------+---------------------------+-------+---------+
5 rows in set (0.01 sec)
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