MYSQL的一些命令

展示指定表的所有列详细信息

mysql> show full columns from settle;
+-----------+---------------+-----------------+------+-----+---------+----------------+---------------------------------+-----------------+
| Field     | Type          | Collation       | Null | Key | Default | Extra          | Privileges                      | Comment         |
+-----------+---------------+-----------------+------+-----+---------+----------------+---------------------------------+-----------------+
| id        | int(11)       | NULL            | NO   | PRI | NULL    | auto_increment | select,insert,update,references | 主key           |
| deal_time | int(11)       | NULL            | NO   |     | NULL    |                | select,insert,update,references | 提交时间        |
| userid    | varchar(32)   | utf8_general_ci | NO   |     | NULL    |                | select,insert,update,references | 用户id          |
| name      | varchar(128)  | utf8_general_ci | NO   |     | NULL    |                | select,insert,update,references | 店铺名称        |
| contact   | varchar(32)   | utf8_general_ci | NO   |     | NULL    |                | select,insert,update,references | 联系人          |
| location  | varchar(1024) | utf8_general_ci | NO   |     | NULL    |                | select,insert,update,references | 店铺地址        |
| phone     | varchar(32)   | utf8_general_ci | NO   |     | NULL    |                | select,insert,update,references | 手机号码        |
| note      | text          | utf8_general_ci | YES  |     | NULL    |                | select,insert,update,references | 备注            |
| status    | int(11)       | NULL            | NO   |     | NULL    |                | select,insert,update,references | 是否已处理      |
+-----------+---------------+-----------------+------+-----+---------+----------------+---------------------------------+-----------------+
9 rows in set (0.00 sec)

修改现有表的字符集

ALTER TABLE tablename CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci;