例如以下为mysql必知必会第九章開始：
正則表達式用于匹配特殊的字符集合。mysql通过where子句对正則表達式提供初步的支持。
keywordregexp用来表示后面跟的东西作为正則表達式处理。
（.）是正則表達式的一个符号，表示匹配随意一个字符：
mysql> select prod_name
-> from products
-> where prod_name regexp '.000'
-> order by prod_name;
+--------------+
| prod_name |
+--------------+
| JetPack 1000 |
| JetPack 2000 |
+--------------+
2 rows in set (0.14 sec)
|匹配符：
表示匹配当中之中的一个
mysql> select prod_name
-> from products
-> where prod_name REGEXP '1000|2000'
-> ORDER BY prod_name;
+--------------+
| prod_name |
+--------------+
| JetPack 1000 |
| JetPack 2000 |
+--------------+
2 rows in set (0.00 sec)
[]匹配符： 匹配几个字符之中的一个
2 rows in set (0.00 sec) mysql> select prod_name
-> from products
-> where prod_name regexp '[123] Ton'
-> ;
+-------------+
| prod_name |
+-------------+
| 1 ton anvil |
| 2 ton anvil |
+-------------+
2 rows in set (0.00 sec)
mysql> select prod_name from products where prod_name regexp '[1-5] Ton';
+--------------+
| prod_name |
+--------------+
| .5 ton anvil |
| 1 ton anvil |
| 2 ton anvil |
+--------------+
3 rows in set (0.02 sec)
(^)否定匹配符：
mysql> select prod_name from products where prod_name regexp '[^1-3] Ton';
+--------------+
| prod_name |
+--------------+
| .5 ton anvil |
+--------------+
1 row in set (0.00 sec)
匹配特殊字符，必须用\\为前导。
mysql> select prod_name from products where prod_name regexp '\\.' ;
+--------------+
| prod_name |
+--------------+
| .5 ton anvil |
+--------------+
1 row in set (0.00 sec)
匹配字符类：
mysql> select prod_name from products where prod_name REGEXP '\\([0-9] sticks?\\)' order by prod_name;
+----------------+
| prod_name |
+----------------+
| TNT (1 stick) |
| TNT (5 sticks) |
+----------------+
2 rows in set (0.05 sec) mysql> select prod_name from products where prod_name REGEXP '[[:digit:]]{4}' order by prod_name;
+--------------+
| prod_name |
+--------------+
| JetPack 1000 |
| JetPack 2000 |
+--------------+
2 rows in set (0.00 sec)
定位符使用方法：
mysql> select prod_name
-> from products
-> where prod_name REGEXP '^[0-9\\.]'
-> order by prod_name;
+--------------+
| prod_name |
+--------------+
| .5 ton anvil |
| 1 ton anvil |
| 2 ton anvil |
+--------------+
3 rows in set (0.00 sec)