How to change the database server (MySQL and MariaDB) default charset from "utf8_unicode_ci" to "utf8mb4_unicode_ci" in MySQL in Plesk for Linux?

1. Connect to a Plesk server via SSH.

2. Create the file /root/dbscript.sh with the following content:

   CONFIG_TEXT: #!/bin/sh
   
   db=${NEW_DATABASE_NAME}
   
   plesk db "ALTER DATABASE $db CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci"

3. Set the correct permissions:

   # chmod 0775 /root/dbscript.sh

4. In Plesk, go to Tools & Settings > Event Manager and click Add Event Handler.

5. Choose the event type to be Database created, put the following in the command section and press OK:

   CONFIG_TEXT: /root/dbscript.sh

   
   

Warning: These changes affect in database creation that is done directly in MySQL and MariaDB and is not done via Plesk inteaction.

1. Log into the server via SSH.

2. Open the /etc/my.cnf file with the vi text editor and add the following lines under the corresponding sections:

   Note: for example if the default-character-set line already specified replace its value with utf8mb4.

   CONFIG_TEXT: [client]
   default-character-set = utf8mb4
   
   [mysql]
   default-character-set = utf8mb4
   

3. 
   [mysqld]
   character-set-server = utf8mb4
   collation-server = utf8mb4_unicode_ci

4. Restart the MariaDB service to apply the changes:

   # service mariadb restart