LCASE() 函数

把字段的值转换为小写。

SQL LCASE() 语法

SELECT LCASE(column_name) FROM table_name;

用于 SQL Server 的语法

SELECT LOWER(column_name) FROM table_name;

示例

"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  | 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     |
+----+---------------+---------------------------+-------+---------+

从 "Websites" 表中选取 "name" 和 "url" 列，并把 "name" 列的值转换为小写：

SELECT LCASE(name) AS site_title, url
FROM Websites;

输出结果：

mysql> SELECT LCASE(name) AS site_title, url
    -> FROM Websites;

+---------------+----------------------------+
| site_title    |  url                       |
+---------------+----------------------------+
| google        |   https://www.google.cm/   |
| 淘宝          |  https://www.taobao.com/    |
| 菜鸟教程       |  urhttp://www.runoob.com/  |
| 微博          |  http://weibo.com/          |
| fackbool      |  https://www.facebook.com/ |
| stackverflow |  http://stackoverflow.com/  |
+---------------+----------------------------+