MySQL 中的 RLIKE运算符

喜欢：
MySQL 中的此运算符用于执行字符串表达式与模式的模式匹配。

句法 ：

RLIKE pattern

参数 ：
此方法接受语法中提到的一个参数。

• 模式 –我们要与表达式匹配的模式。下面描述了各种模式及其用法。

Pattern	What the Pattern matches
*	Zero or more instances of string preceding it
+	One or more instances of strings preceding it
.	Any single character
?	Match zero or one instances of the strings preceding it.
^	caret(^) matches Beginning of string
$	End of string
[abc]	Any character listed between the square brackets
[^abc]	Any character not listed between the square brackets
[A-Z]	match any upper case letter.
[a-z]	match any lower case letter
[0-9]	match any digit from 0 through to 9.
[[:<:]]	matches the beginning of words.
[[:>:]]	matches the end of words.
[:class:]	matches a character class i.e. [:alpha:] to match letters, [:space:] to match white space, [:punct:] is match punctuations and [:upper:] for upper class letters.
p1|p2|p3	Alternation; matches any of the patterns p1, p2, or p3
{n}	n instances of preceding element
{m,n}	m through n instances of preceding element

示例-1：
以下示例查找姓氏以字母 S 开头的员工。

CREATE TABLE Employee
(
Employee_id INT AUTO_INCREMENT,  
First_name VARCHAR(100) NOT NULL,
Last_name VARCHAR(100) NOT NULL,
Joining_Date DATE NOT NULL,
PRIMARY KEY(Employee_id )
);

向 Employee 表插入一些数据：

INSERT INTO Employee
(First_name ,Last_name , Joining_Date )
VALUES
('Sayantan', 'Majumdar', '2000-01-11'),
('Anushka', 'Samanta', '2002-11-10' ),
('Sayan', 'Sharma', '2005-06-11' ),
('Shayari', 'Das', '2008-01-21' ),
('Sayani', 'Jain', '2008-02-01' ),
('Tapan', 'Samanta', '2010-01-11' ),
('Deepak', 'Sharma', '2014-12-01'  ),
('Ankana', 'Jana', '2018-08-17'),
('Shreya', 'Ghosh', '2020-09-10') ;

因此，员工表如下。

select * from Employee ;

输出 ：

Employee_id	First_name	Last_name	Joining_Date
1	Sayantan	Majumdar	2000-01-11
2	Anushka	Samanta	2002-11-10
3	Sayan	Sharma	2005-06-11
4	Shayari	Das	2008-01-21
5	Sayani	Jain	2008-02-01
6	Tapan	Samanta	2010-01-11
7	Deepak	Sharma	2014-12-01
8	Ankana	Jana	2018-08-17
9	Shreya	Ghosh	2020-09-10

现在，我们将检查姓氏为“S”的员工。

SELECT * FROM Employee   
WHERE Last_name RLIKE '^S' ;

输出 ：

Employee_id	First_name	Last_name	Joining_Date
2	Anushka	Samanta	2002-11-10
3	Sayan	Sharma	2005-06-11
6	Tapan	Samanta	2010-01-11
7	Deepak	Sharma	2014-12-01

示例 2 ：
以下示例查找名字以字母“i”结尾的员工。

SELECT * FROM Employee   
WHERE First_name RLIKE 'i$' ;

输出 ：

Employee_id	First_name	Last_name	Joining_Date
4	Shayari	Das	2008-01-21
5	Sayani	Jain	2008-02-01