在MySql中使用正则可以达到事半功倍的效果,在php,asp中都有正则表达式这一说那么mysql是怎么样的呢,下面我拿一个实例 查找筛选字段为中文的记录sql语句。
如,简单看示例,使用mysql筛选出某字段中文的记录:
代码如下 | 复制代码 |
select * from table where not name regexp '^[1-9A-Za-z]'; |
实例
数据库例:
entry name cost
-----------------------------------------------------------------
123 魔法披风 100
124 角斗士勋章 200
125 Maxcuh 300
126 勇者徽章 400
127 Ulisanise 500
128 HP回复 600
要求只把125和127列出来
代码如下 | 复制代码 |
SELECT column_name FROM `table_name` WHERE column_name regexp "[[:alpha:]]+";中的 "[[:alpha:]]+" |
alpha代表英文字母,意思是只把全是英文字母的列挑出来.
SELECT * FROM `your_table_name` WHERE name regexp "[[:alpha:]]+";.
常用的正则字符串匹配
所匹配的字符串以后面的字符串开头
代码如下 | 复制代码 |
mysql> select "fonfo" REGEXP "^fo$"; -> 0(表示不匹配) mysql> select "fofo" REGEXP "^fo"; -> 1(表示匹配) $ |
所匹配的字符串以前面的字符串结尾
代码如下 | 复制代码 |
mysql> select "fono" REGEXP "^fono$"; -> 1(表示匹配) mysql> select "fono" REGEXP "^fo$"; -> 0(表示不匹配) |
.
匹配任何字符(包括新行)
代码如下 | 复制代码 |
mysql> select "fofo" REGEXP "^f.*"; -> 1(表示匹配) mysql> select "fonfo" REGEXP "^f.*"; -> 1(表示匹配) a* |
匹配任意多个a(包括空串)
代码如下 | 复制代码 |
mysql> select "Ban" REGEXP "^Ba*n"; -> 1(表示匹配) mysql> select "Baaan" REGEXP "^Ba*n"; -> 1(表示匹配) mysql> select "Bn" REGEXP "^Ba*n"; -> 1(表示匹配) a+ |
匹配任意多个a(不包括空串)
代码如下 | 复制代码 |
mysql> select "Ban" REGEXP "^Ba+n"; -> 1(表示匹配) mysql> select "Bn" REGEXP "^Ba+n"; -> 0(表示不匹配) a? |
匹配一个或零个a
代码如下 | 复制代码 |
mysql> select "Bn" REGEXP "^Ba?n"; -> 1(表示匹配) mysql> select "aXbc" REGEXP "^[a-dXYZ]+$"; -> 1(表示匹配) mysql> select "aXbc" REGEXP "^[^a-dXYZ]+$"; -> 0(表示不匹配) mysql> select "gheis" REGEXP "^[^a-dXYZ]+$"; -> 1(表示匹配) mysql> select "gheisa" REGEXP "^[^a-dXYZ]+$"; -> 0(表示不匹配) |
------------------------------------------------------------
[[.characters.]]
表示比较元素的顺序。在括号内的字符顺序是唯一的。但是括号中可以包含通配符, 所以他能匹配更多的字符。举例来说:正则表达式[[.ch.]]*c匹配chchcc的前五个字符。
[=character_]
表示相等的类,可以代替类中其他相等的元素,包括它自己。例如,如果o和(+)是一个相等的类的成员,那么[[=o=]]、[[=(+)=]]和[o(+)]是完全等价的。
[:character_class:]
在括号里面,在[:和:]中间是字符类的名字,可以代表属于这个类的所有字符。
字符类的名字有: alnum、digit、punct、alpha、graph、space、blank、lower、upper、cntrl、print和xdigit
代码如下 | 复制代码 |
mysql> select "justalnums" REGEXP "[[:alnum:]]+"; -> 1(表示匹配) mysql> select "!!" REGEXP "[[:alnum:]]+"; -> 0(表示不匹配) |
[[::]]
分别匹配一个单词开头和结尾的空的字符串,这个单词开头和结尾都不是包含在alnum中的字符也不能是下划线。
代码如下 | 复制代码 |
mysql> select "a word a" REGEXP "[[::]]"; -> 1(表示匹配) mysql> select "a xword a" REGEXP "[[::]]"; -> 0(表示不匹配) mysql> select "weeknights" REGEXP "^(wee|week)(knights|nights)$"; -> 1 |

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