sql 基础--mysql 5 （2）

7.利用正则表达式筛选 regexp

mysql> select * from pw_luck where msg regexp '1000';
+-----+-----------+------+
| uid | name      | msg  |
+-----+-----------+------+
|   7 | zhangsan7 | 1000 |
|   8 | zhangsan8 | 1000 |
|   9 | zhangsan9 | 1000 |
|  10 | wang5     | 1000 |
+-----+-----------+------+
4 rows in set (0.00 sec)

　　like 和 正则匹配 一般情况下不区分大小写  除非加入关键字 binary

mysql> select * from pw_luck where name like 'wang%';
+-----+--------+------+
| uid | name   | msg  |
+-----+--------+------+
|   3 | wang5  | 1001 |
|  10 | wang5  | 1000 |
|  11 | wang5% | 2000 |
|  12 | WANG5  | 1000 |
+-----+--------+------+
4 rows in set (0.00 sec)

mysql> select * from pw_luck where name like binary 'wang%';
+-----+--------+------+
| uid | name   | msg  |
+-----+--------+------+
|   3 | wang5  | 1001 |
|  10 | wang5  | 1000 |
|  11 | wang5% | 2000 |
+-----+--------+------+
3 rows in set (0.00 sec)

　　范围 []

mysql> select * from pw_luck where name regexp 'zhangsan[1-9]'
    -> ;
+-----+-----------+------+
| uid | name      | msg  |
+-----+-----------+------+
|   7 | zhangsan7 | 1000 |
|   8 | zhangsan8 | 1000 |
|   9 | zhangsan9 | 1000 |
+-----+-----------+------+
3 rows in set (0.00 sec)

mysql> select * from pw_luck where name regexp 'zhangsan[789]';
+-----+-----------+------+
| uid | name      | msg  |
+-----+-----------+------+
|   7 | zhangsan7 | 1000 |
|   8 | zhangsan8 | 1000 |
|   9 | zhangsan9 | 1000 |
+-----+-----------+------+
3 rows in set (0.00 sec)

zhangsan[789]也可以写成 zhangsan[7|8|9]

转义字符： | 【】 - . 等

元字符：* 0个或多个
　　　　+ 1个或多个
　　　　? 0个或1个
　　　　{n} 指定数目
　　　　{n,}
　　　　{n,m} 范围
定位符  ^开始位置 （【】外，【】内是非的意思）
　　　　$文本结尾

mysql> select * from pw_luck where name regexp '^[l]';
+-----+------+------+
| uid | name | msg  |
+-----+------+------+
|   2 | lisi | 1001 |
+-----+------+------+
1 row in set (0.00 sec)

mysql> select * from pw_luck where name regexp 'l';
+-----+--------+------+
| uid | name   | msg  |
+-----+--------+------+
|   0 | Wilson |  100 |
|   2 | lisi   | 1001 |
+-----+--------+------+
2 rows in set (0.00 sec)