MySQL regular expression

MySQL Regular expressions

Introduce

Regular expressions （regular expression） Describes a string matching rule , The regular expression itself is a string , Use this string to describe 、 To define rules , Matches a series of strings that conform to a syntax rule .

In development , Regular expressions are often used to retrieve , Replace the text that conforms to a rule .

MySQL Use REGEXP Keyword supports string matching with regular expressions .

Format

Pattern	describe
^	Matches the start of the input string
$	Matches the end of the input string
.	Matching elimination \n Any single character other than
[…]	Character set . Matches any of the contained characters , for example ：[‘abc’] Can match "plain" Medium a
[^…]	Negative character set . Match any character not included . for example ：[‘abc’] Can match "plain" Medium p
p1|p2|p3	matching p1 perhaps p2 or p3. for example ：'z|food’ Can match "z" perhaps "food"."(z|f)ood" matching "zood" perhaps "food"
*	Matches the previous subexpression zero or more times . for example ：zo* Can match "z" as well as zoo.
+	Match the previous subexpression one or more times
{n}	n Is a non negative integer , Matched definite n Time
{n,m}	m and n All non negative integers , among n <= m. Least match n Times and at most m Time

The operation sample

-- ^  start   Search for items with names beginning with sea in the item table 
select * from product where pname REGEXP '^ The sea ';

-- .  Match any single character 
select 'abc' REGEXP '.b';