建立表添加註釋

CREATE TABLE purchase(
                id int(25) PRIMARY KEY AUTO_INCREMENT, 
                user_id int(50) COMMENT'列註釋',  
                created_on  datetime default NULL
            )ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='表註釋';

查看錶註釋：

SELECT tableName,tableComment 
    FROM
 
 information_schema.tables 
    WHERE table_schema = '所在db' 
    AND table_name = '表名稱';
或者：
SHOW CREATE TABLE purchase;

修改註釋

ALTER TABLE purchase COMMENT '新的表註釋';
ALTER TABLE purchase MODIFY COLUMN user_id VARCHAR(25) COMMENT '新的列註釋';

檢視列註釋

SHOW FULL COLUMNS FROM purchase;
也可安條件查詢
SHOW FULL
 
 COLUMNS FROM purchase 
    WHERE FIELD = 'user_id' 
    OR TYPE LIKE '%int%' 
-- 檢視purchase表中列名是user_id的或型別是int的列