Question about character encoding between php web pages and mysql?

Generally, PHP and mysql involve the character types of the 2..html or. php file in the metatag of 1.html. 3. character set of the database in mysql. 4. character encoding of fields in the table. So how should we set the character encoding above to prevent Chinese characters from being garbled in the database or in the front end? Character encoding of mysqlphp front-end database

Generally, in php and mysql, there are four locations involved in character encoding.
1. in the meta tag of html
2..html or. php file character type
3. character set of databases in mysql
4. character encoding of fields in the table.

To prevent Chinese characters from being garbled in the database or in the front end,
How should I set the character encoding above?