SQL 学习之BETWEEN 操作符

说明：
BETWEEN 操作符用于选取介于两个值之间的数据范围内的值。
语法：

SELECT column_name(s)
FROM table_name
WHERE column_name BETWEEN value1 AND value2;

演示库

+----+--------------+---------------------------+-------+---------+
| id | name         | url                       | alexa | country |
+----+--------------+---------------------------+-------+---------+
| 1  | Google       | https://www.google.cm/    | 1     | USA     |
| 2  | 淘宝          | https://www.taobao.com/   | 13    | CN      |
| 3  | 菜鸟教程      | http://www.runoob.com/    | 4689  | CN      |
| 4  | 微博          | http://weibo.com/         | 20    | CN      |
| 5  | Facebook     | https://www.facebook.com/ | 3     | USA     |
| 7  | stackoverflow | http://stackoverflow.com/ |   0 | IND     |
+----+---------------+---------------------------+-------+---------+

BETWEEN 操作符实例，选取 alexa 介于 1 和 20 之间的所有网站：

SELECT * FROM Websites
WHERE alexa BETWEEN 1 AND 20;

NOT BETWEEN 操作符实例，显示不在上面实例范围内的网站，请使用 NOT BETWEEN：

SELECT * FROM Websites
WHERE alexa NOT BETWEEN 1 AND 20;