The use of the MySQL Express expression

The performance of the normal expression in MySQL is higher than like, so here is a summary of the use of regular expressions.

Patterns of regular expressions and their meanings:

The following examples illustrate their usage:

Build Table Student:

CREATE TABLE student (ID int (6) Auto_increment,name Carchar (6), age int (3), primary key (ID)); Insert data: INSERT into student (name , age) VALUES (' Xzb ', (), (' Spal '), (' WGC ', 32);

1.^

Select name from student where name REGEXP ' ^x '; --querying data that begins with X

2.$

SELECT * FROM student where name REGEXP ' C $ '; --Query for data ending in C

3. ".": This character is the English point, it matches any one character, including carriage return, line wrapping and so on.

SELECT * FROM student where name REGEXP ' X. '; --Match the first letter X, the rest of the letter arbitrary data

4.*: An asterisk matches 0 or more characters and must have content before it.

SELECT * FROM student where name REGEXP ' x* '; --match any of the characters

5. "+": the plus sign matches 1 or more characters, and must have content before it.

SELECT * FROM student where name REGEXP ' x* ';--matches any character greater than 1

6. "?": the question mark matches 0 or 1 times.

SELECT * FROM student where name REGEXP ' x? '; --Match 0 or 1 characters

7.xzb|spal|

SELECT * FROM student where name REGEXP ' Xzb|spal ';--match xzb or Spal

8.[x-z]*

SELECT * FROM student where name REGEXP ' ^[x-z] ';--matches data that begins with a character in X, Y, Z

SELECT * FROM student where name REGEXP ' [a-d]$ ';--match data ending with characters in a-d

9.[^x-z]*

SELECT * FROM student where name REGEXP ' ^[^x-z] ';--matches data that does not begin with a character that is not in the X-z

SELECT * FROM student where name REGEXP ' [^h-j]$ ';--matches data that is not at the beginning of a character in X-z

10.{n}

SELECT * FROM student where name REGEXP ' ^s{2} ';--match all data that starts with S and repeats at least 2 times

11.{N,M}

SELECT * FROM student where name REGEXP ' ^s{2,5} ';--match all data that starts with S and repeats 2 to 5 times

The use of the MySQL Express expression