mysql命令行 - 简单的文本模式匹配

在上一节我们学习了有条件查询语句，它们是有关比较操作符的使用，例如: =、!=、>、< 等等。这一节我们要学习：

如何使用文本模式匹配？

使用= 和 != 我们可以判断文本是否相同，如果要判断部分文本是否相同，就可以用到mysql的文本模式匹配 - LIKE

1. LIKE "J%"

LIKE "J%" 匹配起始字母为J的所有字符串包括"J"，例如：

select f_name, l_name from employee_data where f_name = "John";
+--------+------------+
| f_name | l_name     |
+--------+------------+
| John   | Hagan      |
| John   | MacFarland |
+--------+------------+
2 rows in set (0.00 sec)

2. LIKE "%N"

LIKE "%N" 匹配结束字母为N的所有字符串，包括"N"，例如：

mysql> select f_name, l_name from employee_data
where l_name like '%a';
+--------+--------+
| f_name | l_name |
+--------+--------+
| Manish | Sharma |
| Alok   | Nanda  |
| Arthur | Hoopla |
+--------+--------+
3 rows in set (0.00 sec)

3. LIKE "%D%"

LIKE "%D%" 匹配含有字母D的所有字符串，包含"D"

select f_name, l_name, title from employee_data
where title like '%senior%';
+--------+--------+----------------------------+
| f_name | l_name | title                      |
+--------+--------+----------------------------+
| John   | Hagan  | Senior Programmer          |
| Ganesh | Pillai | Senior Programmer          |
| Kim    | Hunter | Senior Web Designer        |
| Mike   | Harper | Senior Marketing Executive |
+--------+--------+----------------------------+
4 rows in set (0.00 sec)