正则表达式(Regular Expression),是指一个用来描述或者匹配一系列符合某个语句规则的字符串的单个字符.在MySQL中我们如何使用正则呢?
下面几个小实验例子说明一下:
"^"字符串开始匹配,返回结果为1表示匹配,返回0表示不匹配
mysql> select 'highkyz' regexp '^h';
+-----------------------+
| 'highkyz' regexp '^i' |
+-----------------------+
| 1 |
+-----------------------+
1 row in set (0.00 sec)
"$"字符串末尾匹配
mysql> select 'highkyz' regexp 'z$';
+-----------------------+
| 'highkyz' regexp 'g$' |
+-----------------------+
| 1 |
+-----------------------+
1 row in set (0.00 sec)
"."匹配任意单个字符,包括换行符.
mysql> select 'highkyz' regexp '.q','highkyz' regexp '.k';
+-----------------------+-----------------------+
| 'abcdefg' regexp '.q' | 'abcdefg' regexp '.z' |
+-----------------------+-----------------------+
| 0 | 1 |
+-----------------------+-----------------------+
1 row in set (0.00 sec)
"[...]"匹配出括号内的换行符
mysql> select 'highkyz' regexp "[fhk]";
+--------------------------+
| 'highkyz' regexp "[fhk]" |
+--------------------------+
| 1 |
+--------------------------+
1 row in set (0.00 sec)
"[^...]"匹配不出括号内的任意字符
mysql> select 'efg' regexp "[^XYZ]",'X' regexp "[^XYZ]";
+-----------------------+---------------------+
| 'efg' regexp "[^XYZ]" | 'X' regexp "[^XYZ]" |
+-----------------------+---------------------+
| 1 | 0 |
+-----------------------+---------------------+
1 row in set (0.00 sec)
mysql> create table t(name varchar(20),email varchar(40));
Query OK, 0 rows affected (0.44 sec)
mysql> insert into t values ('shanghai','shanghai@163.com');
Query OK, 1 row affected (0.03 sec)
mysql> insert into t values ('shanghai126','shanghai@126.com');
Query OK, 1 row affected (0.03 sec)
mysql> insert into t values ('shanghai188','shanghai@188.com');
Query OK, 1 row affected (0.02 sec)
mysql> select * from t;
+------------+-------------------+
| name | email |
+------------+-------------------+
| shanghai | shanghai@163.com |
| shanghai126 | shanghai@126.com |
| shanghai188 | shanghai@188.com |
+------------+-------------------+
3 rows in set (0.00 sec)
mysql> select name,email from t where email regexp "@163[.,]com$";
+----------+-----------------+
| name | email |
+----------+-----------------+
| shanghai | shanghai@163.com|
+----------+-----------------+
1 row in set (0.00 sec)
MySQL REGEXP:http://dev.mysql.com/doc/refman/5.6/en/regexp.html#operator_regexp
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