mysql学习--mysql必知必会1

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如下为mysql必知必会第九章开始：

正则表达式用于匹配特殊的字符集合。mysql通过where子句对正则表达式提供初步的支持。

关键字regexp用来表示后面跟的东西作为正则表达式处理。

（.）是正则表达式的一个符号，表示匹配任意一个字符：

mysql> select prod_name    -> from products    -> where prod_name regexp '.000'    -> order by prod_name;+--------------+| prod_name    |+--------------+| JetPack 1000 || JetPack 2000 |+--------------+2 rows in set (0.14 sec)

|匹配符：

表示匹配其中之一

mysql> select prod_name    -> from products    -> where prod_name REGEXP '1000|2000'    -> ORDER BY prod_name;+--------------+| prod_name    |+--------------+| JetPack 1000 || JetPack 2000 |+--------------+2 rows in set (0.00 sec)

[]匹配符：匹配几个字符之一

2 rows in set (0.00 sec)mysql> select prod_name    -> from products    -> where prod_name regexp '[123] Ton'    -> ;+-------------+| prod_name   |+-------------+| 1 ton anvil || 2 ton anvil |+-------------+2 rows in set (0.00 sec)

mysql> select prod_name from products where prod_name regexp '[1-5] Ton';+--------------+| prod_name    |+--------------+| .5 ton anvil || 1 ton anvil  || 2 ton anvil  |+--------------+3 rows in set (0.02 sec)

(^)否定匹配符：

mysql> select prod_name from products where prod_name regexp '[^1-3] Ton';+--------------+| prod_name    |+--------------+| .5 ton anvil |+--------------+1 row in set (0.00 sec)

匹配特殊字符，必须用\\为前导。

mysql> select prod_name from products where prod_name regexp '\\.' ;+--------------+| prod_name    |+--------------+| .5 ton anvil |+--------------+1 row in set (0.00 sec)

匹配字符类：

mysql> select prod_name from products where prod_name REGEXP '\\([0-9] sticks?\\)' order by prod_name;+----------------+| prod_name      |+----------------+| TNT (1 stick)  || TNT (5 sticks) |+----------------+2 rows in set (0.05 sec)mysql> select prod_name from products where prod_name REGEXP '[[:digit:]]{4}' order by prod_name;+--------------+| prod_name    |+--------------+| JetPack 1000 || JetPack 2000 |+--------------+2 rows in set (0.00 sec)

定位符用法：

mysql> select prod_name    -> from products    -> where prod_name REGEXP '^[0-9\\.]'    -> order by prod_name;+--------------+| prod_name    |+--------------+| .5 ton anvil || 1 ton anvil  || 2 ton anvil  |+--------------+3 rows in set (0.00 sec)

以上都是mysql正则表达式的用法。

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