MySQLテーブルのデータタイプを変更するだけです。
既存のユーザー認証情報を表示する方法。
MySQLテーブルのデータタイプを変更するだけです
#替换age的数据类型为int（2）
mysql> desc chengji;
+---------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+---------+-------------+------+-----+---------+-------+
| xuehao | int(6) | NO | | NULL | |
| name | varchar(10) | YES | | NULL | |
| age | int(6) | YES | | NULL | |
| address | varchar(10) | YES | | NULL | |
+---------+-------------+------+-----+---------+-------+
4 rows in set (0.00 sec)
mysql> alter table chengji modify column age int(2);
Query OK, 0 rows affected (0.01 sec)
Records: 0 Duplicates: 0 Warnings: 0
mysql> desc chengji;
+---------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+---------+-------------+------+-----+---------+-------+
| xuehao | int(6) | NO | | NULL | |
| name | varchar(10) | YES | | NULL | |
| age | int(2) | YES | | NULL | |
| address | varchar(10) | YES | | NULL | |
+---------+-------------+------+-----+---------+-------+
4 rows in set (0.00 sec)
承認された情報を承認および表示する方法
ユーザーにログインを許可する方法
mysql> grant all privileges on *.* to 'mha'@'192.168.158.10' identified by 'manager';
Query OK, 0 rows affected (0.00 sec)
mysqlライブラリのuserテーブルに保存されている既存のユーザー認証情報を表示する方法
mysql> select host,user,password from mysql.user;
+----------------+-------------+-------------------------------------------+
| host | user | password |
+----------------+-------------+-------------------------------------------+
| localhost | root | |
| client1 | root | |
| 127.0.0.1 | root | |
| ::1 | root | |
| localhost | | |
| client1 | | |
| 192.168.158.% | myslave | *23AE809DDACAF96AF0FD78ED04B6A265E05AA257 |
| 192.168.158.% | mha | *7D2ABFF56C15D67445082FBB4ACD2DCD26C0ED57 |
| % | mha@server2 | *7D2ABFF56C15D67445082FBB4ACD2DCD26C0ED57 |
| server2 | mha | *7D2ABFF56C15D67445082FBB4ACD2DCD26C0ED57 |
| 192.168.158.10 | mha | *7D2ABFF56C15D67445082FBB4ACD2DCD26C0ED57 |
| 192.168.158.30 | mha | *7D2ABFF56C15D67445082FBB4ACD2DCD26C0ED57 |
| 192.168.158.20 | mha | *7D2ABFF56C15D67445082FBB4ACD2DCD26C0ED57 |
+----------------+-------------+-------------------------------------------+