MySQL 正则表达式详解(2)

mysql> SELECT 'stab' REGEXP '.ta*b';
+-----------------------+
| 'stab' REGEXP '.ta*b' |
+-----------------------+
|                    1 |
+-----------------------+
row in set (0.00 sec)
mysql> SELECT 'stb' REGEXP '.ta*b';
+----------------------+
| 'stb' REGEXP '.ta*b' |
+----------------------+
|                    1 |
+----------------------+
 
mysql> SELECT '' REGEXP 'a*';
+----------------+
| '' REGEXP 'a*' |
+----------------+
|              1 |
+----------------+
1 row in set (0.00 sec)

　　

a+

匹配1个或者多个a,但是不包括空字符

mysql> SELECT 'stab' REGEXP '.ta+b';
+-----------------------+
| 'stab' REGEXP '.ta+b' |
+-----------------------+
|                    1 |
+-----------------------+
row in set (0.00 sec)
 
mysql> SELECT 'stb' REGEXP '.ta+b';
+----------------------+
| 'stb' REGEXP '.ta+b' |
+----------------------+
|                    0 |
+----------------------+
row in set (0.00 sec)

　　

a?

匹配0个或者1个a

mysql> SELECT 'stb' REGEXP '.ta?b';
+----------------------+
| 'stb' REGEXP '.ta?b' |
+----------------------+
|                    1 |
+----------------------+
row in set (0.00 sec)
 
mysql> SELECT 'stab' REGEXP '.ta?b';
+-----------------------+
| 'stab' REGEXP '.ta?b' |
+-----------------------+
|                    1 |
+-----------------------+
row in set (0.00 sec)
 
mysql> SELECT 'staab' REGEXP '.ta?b';
+------------------------+
| 'staab' REGEXP '.ta?b' |
+------------------------+
|                      0 |
+------------------------+
row in set (0.00 sec)

a1|a2

匹配a1或者a2，

mysql> SELECT 'a' REGEXP 'a|b';
+------------------+
| 'a' REGEXP 'a|b' |
+------------------+
|                1 |
+------------------+
row in set (0.00 sec)
 
mysql> SELECT 'b' REGEXP 'a|b';
+------------------+
| 'b' REGEXP 'a|b' |
+------------------+
|                1 |
+------------------+
row in set (0.00 sec)
 
mysql> SELECT 'b' REGEXP '^(a|b)';
+---------------------+
| 'b' REGEXP '^(a|b)' |
+---------------------+
|                  1 |
+---------------------+
row in set (0.00 sec)
 
mysql> SELECT 'a' REGEXP '^(a|b)';
+---------------------+
| 'a' REGEXP '^(a|b)' |
+---------------------+
|                  1 |
+---------------------+
row in set (0.00 sec)
 
mysql> SELECT 'c' REGEXP '^(a|b)';
+---------------------+
| 'c' REGEXP '^(a|b)' |
+---------------------+
|                  0 |
+---------------------+
row in set (0.00 sec)

　注意：^符合只有在[]内才是取反的意思，在别的地方都是表示开始处匹配　

　

a{m}

匹配m个a

mysql> SELECT 'auuuuc' REGEXP 'au{4}c';
+--------------------------+
| 'auuuuc' REGEXP 'au{4}c' |
+--------------------------+
|                        1 |
+--------------------------+
row in set (0.00 sec)
 
mysql> SELECT 'auuuuc' REGEXP 'au{3}c';
+--------------------------+
| 'auuuuc' REGEXP 'au{3}c' |
+--------------------------+
|                        0 |
+--------------------------+
row in set (0.00 sec)

　　

a{m,}

匹配m个或者更多个a