show variables like "%character%";
set character_set_server=utf8mb4;
 
或者修改/etc/my.cnf或者/etc/mysql/my.cnf
[client]
default-character-set = utf8mb4
[mysqld]
default-storage-engine = INNODB
character-set-server = utf8mb4
collation-server = utf8mb4_general_ci