1,desc tablename;

mysql> desc authors;
+-------+--------------+------+-----+---------+----------------+
| Field | Type         | Null | Key | Default | Extra          |
+-------+--------------+------+-----+---------+----------------+
| id    | int(11)      | NO   | PRI | NULL    | auto_increment |
| email | varchar(100) | NO   | UNI | NULL    |                |
| name  | varchar(100) | NO   |     | NULL    |                |
+-------+--------------+------+-----+---------+----------------+
3 rows in set

2,show create table tablename; 

mysql> show create table authors;
+---------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Table   | Create Table                                                                                                                                                                                                                           |
+---------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| authors | CREATE TABLE `authors` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `email` varchar(100) NOT NULL,
  `name` varchar(100) NOT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `email` (`email`)
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8 |
+---------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set

3,select * from columns where table_name='表名'

mysql> use information_schema;
Database changed
mysql> select * from columns where table_name='authors';
+---------------+--------------+------------+-------------+------------------+----------------+-------------+-----------+--------------------------+------------------------+-------------------+---------------+--------------------+-----------------+--------------+------------+----------------+---------------------------------+----------------+
| TABLE_CATALOG | TABLE_SCHEMA | TABLE_NAME | COLUMN_NAME | ORDINAL_POSITION | COLUMN_DEFAULT | IS_NULLABLE | DATA_TYPE | CHARACTER_MAXIMUM_LENGTH | CHARACTER_OCTET_LENGTH | NUMERIC_PRECISION | NUMERIC_SCALE | CHARACTER_SET_NAME | COLLATION_NAME | COLUMN_TYPE | COLUMN_KEY | EXTRA | PRIVILEGES | COLUMN_COMMENT |
+---------------+--------------+------------+-------------+------------------+----------------+-------------+-----------+--------------------------+------------------------+-------------------+---------------+--------------------+-----------------+--------------+------------+----------------+---------------------------------+----------------+
| def | zqad | authors | id | 1 | NULL | NO | int | NULL | NULL | 10 | 0 | NULL | NULL | int(11) | PRI | auto_increment | select,insert,update,references | |
| def | zqad | authors | email | 2 | NULL | NO | varchar | 100 | 300 | NULL | NULL | utf8 | utf8_general_ci | varchar(100) | UNI | | select,insert,update,references | |
| def | zqad | authors | name | 3 | NULL | NO | varchar | 100 | 300 | NULL | NULL | utf8 | utf8_general_ci | varchar(100) | | | select,insert,update,references | |
+---------------+--------------+------------+-------------+------------------+----------------+-------------+-----------+--------------------------+------------------------+-------------------+---------------+--------------------+-----------------+--------------+------------+----------------+---------------------------------+----------------+
3 rows in set