MySQL 8.0新特性--Regular Expressions(四)

MySQL8.0暂时支持如下几种正则表达式函数,本文只是抛砖引玉,更多内容请参考MySQL手册。

Name Description
NOT REGEXP Negation of REGEXP
REGEXP Whether string matches regular expression
REGEXP_INSTR() Starting index of substring matching regular expression
REGEXP_LIKE() Whether string matches regular expression
REGEXP_REPLACE() Replace substrings matching regular expression
REGEXP_SUBSTR() Return substring matching regular expression
RLIKE Whether string matches regular expression

regexp、rlike、regexp_like()三者功能相同,只是写法不同

not regexp是否定形式

mysql> select 'abc' regexp '^a';
+-------------------+
| 'abc' regexp '^a' |
+-------------------+
|                 1 |
+-------------------+
1 row in set (0.00 sec)

mysql> select 'abc' rlike '^a';
+------------------+
| 'abc' rlike '^a' |
+------------------+
|                1 |
+------------------+
1 row in set (0.00 sec)

mysql> select regexp_like('abc','^a');
+-------------------------+
| regexp_like('abc','^a') |
+-------------------------+
|                       1 |
+-------------------------+
1 row in set (0.00 sec)

mysql> select 'abc' not regexp '^a';
+-----------------------+
| 'abc' not regexp '^a' |
+-----------------------+
|                     0 |
+-----------------------+
1 row in set (0.00 sec)

mysql> select not regexp_like('abc','^a');
+-----------------------------+
| not regexp_like('abc','^a') |
+-----------------------------+
|                           0 |
+-----------------------------+
1 row in set (0.00 sec)

regexp_replace()替代函数

mysql> select regexp_replace('a1,b2,c3','[a-z]{1}','b');
+-------------------------------------------+
| regexp_replace('a1,b2,c3','[a-z]{1}','b') |
+-------------------------------------------+
| b1,b2,b3                                  |
+-------------------------------------------+
1 row in set (0.00 sec)

mysql> select regexp_replace('aaa,b2,c3','[a-z]{2}','d');
+--------------------------------------------+
| regexp_replace('aaa,b2,c3','[a-z]{2}','d') |
+--------------------------------------------+
| da,b2,c3                                   |
+--------------------------------------------+
1 row in set (0.00 sec)

regexp_substr() 截断字符串

mysql> select regexp_substr('a1,b1,c1,ddds','[a-z 0-9]{1,9}',1,1);
+-----------------------------------------------------+
| regexp_substr('a1,b1,c1,ddds','[a-z 0-9]{1,9}',1,1) |
+-----------------------------------------------------+
| a1                                                  |
+-----------------------------------------------------+
1 row in set (0.00 sec)

mysql> select regexp_substr('a1,b1,c1,ddds','[a-z 0-9]{1,9}',1,2);
+-----------------------------------------------------+
| regexp_substr('a1,b1,c1,ddds','[a-z 0-9]{1,9}',1,2) |
+-----------------------------------------------------+
| b1                                                  |
+-----------------------------------------------------+
1 row in set (0.00 sec)

mysql> select regexp_substr('a1,b1,c1,ddds','[a-z 0-9]{1,9}',1,3);
+-----------------------------------------------------+
| regexp_substr('a1,b1,c1,ddds','[a-z 0-9]{1,9}',1,3) |
+-----------------------------------------------------+
| c1                                                  |
+-----------------------------------------------------+
1 row in set (0.00 sec)

mysql> select regexp_substr('a1,b1,c1,ddds','[a-z 0-9]{1,9}',1,4);
+-----------------------------------------------------+
| regexp_substr('a1,b1,c1,ddds','[a-z 0-9]{1,9}',1,4) |
+-----------------------------------------------------+
| ddds                                                |
+-----------------------------------------------------+
1 row in set (0.00 sec)

regexp_instr() 返回匹配的字符串开始位置index.

mysql> select regexp_instr('dogcatdog','dog',1);
+-----------------------------------+
| regexp_instr('dogcatdog','dog',1) |
+-----------------------------------+
|                                 1 |
+-----------------------------------+
1 row in set (0.00 sec)

mysql> select regexp_instr('dogcatdog','dog',2);
+-----------------------------------+
| regexp_instr('dogcatdog','dog',2) |
+-----------------------------------+
|                                 7 |
+-----------------------------------+
1 row in set (0.00 sec)

mysql> select regexp_instr('a aa aaa aaaa','a{3}',1);
+----------------------------------------+
| regexp_instr('a aa aaa aaaa','a{3}',1) |
+----------------------------------------+
|                                      6 |
+----------------------------------------+
1 row in set (0.00 sec)


更多内容请参考如下链接

12.5.2 Regular Expressions

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转载自blog.51cto.com/darrenmemos/2327937