MySQL Learning--mysql must be known 1

?? For example, the following is the Nineth chapter of MySQL must be known to start:

The normal form is used to match a particular character set. MySQL provides preliminary support for the regular form through the WHERE clause.

Keywordregexp is used to denote what is followed as a form of processing.

(.) is a symbol of a regular expression that matches a random character:

Mysql> Select Prod_name, from Products,    where Prod_name regexp '. ORDER by    prod_name;+ --------------+| Prod_name    |+--------------+| JetPack 1000 | | JetPack |+--------------+2 rows in Set (0.14 sec)

| match character:

Represents one of the matches among

Mysql> Select Prod_name, from Products,    where Prod_name REGEXP ' 1000|2000 '    ORDER by Prod_n ame;+--------------+| Prod_name    |+--------------+| JetPack 1000 | | JetPack |+--------------+2 rows in Set (0.00 sec)

[] Match: Matches one of several characters

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 s Ec

(^) Negative match:

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)

To match Special characters, you must use \ \ as the leading.

Mysql> Select Prod_name from Products where prod_name regexp ' \ \. '; +--------------+| Prod_name    |+--------------+|. 5 ton Anvil |+--------------+1 row in Set (0.00 sec)

Match character class:

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 ' [[:d igit:]]{4} ' ORDER by prod_name;+--------------+| Prod_name    |+--------------+| JetPack 1000 | | JetPack |+--------------+2 rows in Set (0.00 sec)

How to use Locators:

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 s Ec

These are the methods used by MySQL in the form of expressions.