Home >Database >Mysql Tutorial >mysql学习--mysql必知必会1_MySQL

mysql学习--mysql必知必会1_MySQL

WBOY
WBOYOriginal
2016-06-01 13:13:521144browse

如下为mysql必知必会第九章开始:

正则表达式用于匹配特殊的字符集合。mysql通过where子句对正则表达式提供初步的支持。

关键字regexp用来表示后面跟的东西作为正则表达式处理。

(.)是正则表达式的一个符号,表示匹配任意一个字符:

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:

表示匹配其中之一

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: 匹配几个字符之一

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)
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)

定位符用法:

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)


以上都是mysql正则表达式的用法。

Statement:
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn