联合索引比合并索引效率高。
创建用户并且给用户设置权限和密码。（设置指定的ｉｐ或任意％）
grant select权限 on class1804n.usersinfo 数据库名字.表名to 'zangsan'用户名@'%主机ｉｐ' indentified by '1111密码'
超出权限报错
ERROR 1142 (42000): UPDATE command denied to user 'zangsan'@'localhost' for table 'usersinfo'
查看密码
mysql> use mysql;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
mysql> desc user;
+------------------------+-----------------------------------+------+-----+-----------------------+-------+
| Field | Type | Null | Key | Default | Extra |
+------------------------+-----------------------------------+------+-----+-----------------------+-------+
| Host | char(60) | NO | PRI | | |
| User | char(32) | NO | PRI | | |
| Select_priv | enum('N','Y') | NO | | N | |
| Insert_priv | enum('N','Y') | NO | | N | |
| Update_priv | enum('N','Y') | NO | | N | |
| Delete_priv | enum('N','Y') | NO | | N | |
| Create_priv | enum('N','Y') | NO | | N | |
| Drop_priv | enum('N','Y') | NO | | N | |
| Reload_priv | enum('N','Y') | NO | | N | |
| Shutdown_priv | enum('N','Y') | NO | | N | |
| Process_priv | enum('N','Y') | NO | | N | |
| File_priv | enum('N','Y') | NO | | N | |
| Grant_priv | enum('N','Y') | NO | | N | |
| References_priv | enum('N','Y') | NO | | N | |
| Index_priv | enum('N','Y') | NO | | N | |
| Alter_priv | enum('N','Y') | NO | | N | |
| Show_db_priv | enum('N','Y') | NO | | N | |
| Super_priv | enum('N','Y') | NO | | N | |
| Create_tmp_table_priv | enum('N','Y') | NO | | N | |
| Lock_tables_priv | enum('N','Y') | NO | | N | |
| Execute_priv | enum('N','Y') | NO | | N | |
| Repl_slave_priv | enum('N','Y') | NO | | N | |
| Repl_client_priv | enum('N','Y') | NO | | N | |
| Create_view_priv | enum('N','Y') | NO | | N | |
| Show_view_priv | enum('N','Y') | NO | | N | |
| Create_routine_priv | enum('N','Y') | NO | | N | |
| Alter_routine_priv | enum('N','Y') | NO | | N | |
| Create_user_priv | enum('N','Y') | NO | | N | |
| Event_priv | enum('N','Y') | NO | | N | |
| Trigger_priv | enum('N','Y') | NO | | N | |
| Create_tablespace_priv | enum('N','Y') | NO | | N | |
| ssl_type | enum('','ANY','X509','SPECIFIED') | NO | | | |
| ssl_cipher | blob | NO | | NULL | |
| x509_issuer | blob | NO | | NULL | |
| x509_subject | blob | NO | | NULL | |
| max_questions | int(11) unsigned | NO | | 0 | |
| max_updates | int(11) unsigned | NO | | 0 | |
| max_connections | int(11) unsigned | NO | | 0 | |
| max_user_connections | int(11) unsigned | NO | | 0 | |
| plugin | char(64) | NO | | mysql_native_password | |
| authentication_string | text | YES | | NULL | |
| password_expired | enum('N','Y') | NO | | N | |
| password_last_changed | timestamp | YES | | NULL | |
| password_lifetime | smallint(5) unsigned | YES | | NULL | |
| account_locked | enum('N','Y') | NO | | N | |
+------------------------+-----------------------------------+------+-----+-----------------------+-------+
45 rows in set (0.00 sec)
mysql> select user,host,authentication_string from user;
+------------------+-----------+-------------------------------------------+
| user | host | authentication_string |
+------------------+-----------+-------------------------------------------+
| root | localhost | *89C6B530AA78695E257E55D63C00A6EC9AD3E977 |
| mysql.session | localhost | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE |
| mysql.sys | localhost | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE |
| debian-sys-maint | localhost | *A21C5E9583F965AD0F3E7954BD4E6B415BE5A9A9 |
| root | % | *89C6B530AA78695E257E55D63C00A6EC9AD3E977 |
+------------------+-----------+-------------------------------------------+
5 rows in set (0.00 sec)
mysql> grant select on class1804n.usersinfo to 'zangsan'@'%' indentified by '1111';
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'indentified by '1111'' at line 1
mysql> grant select on class1804n.usersinfo to 'zangsan'@'%' identified by '1111';
Query OK, 0 rows affected, 1 warning (0.02 sec)
mysql> select user,host,authentication_string from user; +------------------+-----------+-------------------------------------------+
| user | host | authentication_string |
+------------------+-----------+-------------------------------------------+
| root | localhost | *89C6B530AA78695E257E55D63C00A6EC9AD3E977 |
| mysql.session | localhost | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE |
| mysql.sys | localhost | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE |
| debian-sys-maint | localhost | *A21C5E9583F965AD0F3E7954BD4E6B415BE5A9A9 |
| root | % | *89C6B530AA78695E257E55D63C00A6EC9AD3E977 |
| zangsan | % | *89C6B530AA78695E257E55D63C00A6EC9AD3E977 |
+------------------+-----------+-------------------------------------------+
6 rows in set (0.00 sec)
mysql -u root -p１１１ class1804n < ~/桌面/backup/studentcop.sql;