thinkphp reports an error when executing 'set names utf8mb4'

Running environment: sae + thinkphp
DB_CHARSET is utf8; (setting it directly to utf8mb4 will report an error, I don’t know why...)
If you want to support emoji expressions, the test code is as follows
public function test(){

<code>    $model = M('');
    $model -> query('set names utf8mb4');
}</code>

Error message: [SQL statement]: set names utf8mb4.
Please give me some guidance, thank you!

Reply content:

Running environment: sae + thinkphp
DB_CHARSET is utf8; (setting it directly to utf8mb4 will report an error, I don’t know why...)
If you want to support emoji expressions, the test code is as follows
public function test(){

<code>    $model = M('');
    $model -> query('set names utf8mb4');
}</code>

Error message: [SQL statement]: set names utf8mb4.
Please give me some guidance, thank you!

<code>select version();  看下数据库版本，5.5以上才支持utf8mb4
</code>

Mysql::utf8mb4

1. Check the version of mysql;
Mysql 5.5.3 and later versions add the utf8mb4 character set; previous versions need to upgrade the mysql server first.
2. MySQL utf8mb4 character set
Modify /etc/my.cnf

[client]
default-character-set = utf8mb4

[mysql]
default-character-set = utf8mb4

[mysqld]
character-set-client-handshake = FALSE
character-set-server = utf8mb4
collation-server = utf8mb4_unicode_ci
init_connect='SET NAMES utf8mb4'

Restart MySQL Server and check the character set