How to create a table in mysql and add field comments

#Write comments when creating a table CREATE TABLE userinfo(
	id INT COMMENT 'Number',
	uname VARCHAR(40) COMMENT 'User name',
	address VARCHAR(120) COMMENT 'Home address',
	hobby VARCHAR(200) COMMENT 'hobby'
 
)COMMENT = 'User information table';
 
#Modify the comment of the table ALTER TABLE userinfo COMMENT 'User information table';
 
#Modify the comment of the field. Note: just write the field name and field type. ALTER TABLE userinfo MODIFY COLUMN uname VARCHAR(40) COMMENT 'name';
 
#To view the table comments, see SHOW CREATE TABLE userinfo in the generated SQL statement;
#Look in the metadata table USE information_schema;
SELECT * FROM TABLES WHERE TABLE_SCHEMA='shoppingcart' AND TABLE_NAME='userinfo';
 
#Method to view field comments SHOW FULL COLUMNS FROM userinfo;
#Look in the metadata table SELECT * FROM COLUMNS WHERE TABLE_SCHEMA='shoppingcart' AND TABLE_NAME='userinfo'; 

ALTER TABLE device ADD COLUMN `device_ip` VARCHAR(32) DEFAULT NULL COMMENT 'Device IP';
ALTER TABLE device ADD COLUMN `device_name` VARCHAR(128) DEFAULT NULL COMMENT 'Device name';
ALTER TABLE device ADD COLUMN `device_type` VARCHAR(32) DEFAULT NULL COMMENT 'Device type';

ALTER TABLE device ADD COLUMN 
(`device_ip` VARCHAR(32) DEFAULT NULL COMMENT 'Device IP',
`device_name` VARCHAR(128) DEFAULT NULL COMMENT 'Device name',
`device_type` VARCHAR(32) DEFAULT NULL COMMENT 'Device type');