Mysql string Field 2 ways to determine whether a string is contained _mysql

Suppose you have a table:

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CREATE TABLE users (id int (6) Not NULL auto_increment,primary KEY (ID), user_name VARCHAR (m) not null,emails VARCHAR (x) T NULL);

Initialize the table and add some records.

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TRUNCATE TABLE Users
INSERT into users (user_name, emails) VALUES (' Xiao Zhang ', ' a@email.com,b@email.com,c@email.com ');
INSERT into users (user_name, emails) VALUES (' Xiao Wang ', ' aa@email.com,bb@email.com,cc@email.com ');

　　

Some of the fields in Mysql are string types, how do you find records that contain certain characters?

Method One:

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SELECT * from the users WHERE emails like "%b@email.com%";

So bb@email.com users also found out, not in line with expectations.

Method Two:

Using MySQL string function find_in_set ();

Copy Code code as follows:

SELECT * from Users WHERE find_in_set (' aa@email.com ', emails);

　　

This is possible, how to understand it?

MySQL has a lot of string functions the Find_in_set (STR1,STR2) function is the index of the location where STR1 is returned in str2, and str2 must be split by "."

e.g.

Copy Code code as follows:

MySQL > SELECT find_in_set () (' B ', ' a,a,b,c,d ') as test;
-> 3