Let mysql support emojy expression storage

View MySQL database server and database MySQL character set:

show variables like '%char%';

Check the MySQL character set of the MySQL data table (table):

show table status from database name like '%table name%';

Check the MySQL character set of the MySQL data column (column):

show full columns from 表名;

ALTER TABLE 表名 CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci;