一、用户管理
1、用户账号
用户的账号由用户名和HOST俩部分组成（'USERNAME'@'HOST'）
HOST的表示：
-
主机名
-
具体IP地址
-
网段/掩码
可以使用通配符表示，%和_；192.168.%即表示这个网段的所有主机
2、增加删除账号
主要：在数据库中修改了用户信息需要执行
FLUSH PRIVILEGES;来刷新授权表使其生效
- 创建
MariaDB [mysql]> CREATE USER 'user1'@'192.168.%';
MariaDB [mysql]> CREATE USER 'user2'@'192.168.%' IDENTIFIED BY 'your_password';
MariaDB [mysql]> SELECT user,host,password FROM user;
+-------+-----------+-------------------------------------------+
| user | host | password |
+-------+-----------+-------------------------------------------+
| root | localhost | *4A54C3F37C03C7FBACE31591D6A8C546F93DF5C5 |
| root | centos7 | |
| root | 127.0.0.1 | |
| root | ::1 | |
| | localhost | |
| | centos7 | |
| user1 | 192.168.% | |
| user2 | 192.168.% | *9E72259BA9214F692A85B240647C4D95B0F2E08B |
+-------+-----------+-------------------------------------------+
- 删除
MariaDB [mysql]> DROP USER user2@'192.168.%';
MariaDB [mysql]> SELECT user,host,password FROM user;
+-------+-----------+-------------------------------------------+
| user | host | password |
+-------+-----------+-------------------------------------------+
| root | localhost | *4A54C3F37C03C7FBACE31591D6A8C546F93DF5C5 |
| root | centos7 | |
| root | 127.0.0.1 | |
| root | ::1 | |
| | localhost | |
| | centos7 | |
| user1 | 192.168.% | |
+-------+-----------+-------------------------------------------+
- 重命名
MariaDB [mysql]> RENAME USER user1@'192.168.%' TO testuser@'%';
MariaDB [mysql]> SELECT user,host,password FROM mysql.user;
+----------+-----------+-------------------------------------------+
| user | host | password |
+----------+-----------+-------------------------------------------+
| root | localhost | *4A54C3F37C03C7FBACE31591D6A8C546F93DF5C5 |
| root | centos7 | |
| root | 127.0.0.1 | |
| root | ::1 | |
| | localhost | |
| | centos7 | |
| testuser | % | |
+----------+-----------+-------------------------------------------+
- 修改密码
MariaDB [mysql]> SET PASSWORD FOR testuser@'%' =PASSWORD('testpass');
MariaDB [mysql]> SELECT user,host,password FROM mysql.user;
+----------+-----------+-------------------------------------------+
| user | host | password |
+----------+-----------+-------------------------------------------+
| root | localhost | *4A54C3F37C03C7FBACE31591D6A8C546F93DF5C5 |
| root | centos7 | |
| root | 127.0.0.1 | |
| root | ::1 | |
| | localhost | |
| | centos7 | |
| testuser | % | *00E247AC5F9AF26AE0194B41E1E769DEE1429A29 |
+----------+-----------+-------------------------------------------+
其他修改密码的方法：
UPDATE user SET password=PASSWORD('testpass') WHERE user='testuser';
# mysqladmin -uroot -poldpass password 'newpass'
3、破解管理账号密码
- 空数据库的情况下恢复密码
# systemctl stop mariadb
# rm -rf /var/lib/mysql/* #删库跑路
# systemctl start mariadb
- 有数据的情况下恢复密码
1）在/etc/my.cnf配置文件的[mydqld]下添加skip-grant-tables和skip-networking参数
2）# systemctl restart mariadb 重启服务
3）执行mysql登录到数据库
4）MariaDB [(none)]> UPDATE mysql.user SET password=PASSWORD('newpassword') WHERE user='root' AND host='localhost'; #更新密码
5）MariaDB [(none)]> FLUSH PRIVILEGES; #刷新授权表
6）退出，修改配置文件，删除skip-grant-tables和skip-networking参数，重启服务
也可以在启动mysqld进程时，为其使用如下选项：
--skip-grant-tables
--skip-networking
二、授权管理
1、授权
语法：GRANT priv_type ON [object_type] priv_level TO user@'%' [IDENTIFIED BY 'password'] [WITH GRANT OPTION];
授权时如果用户不存在则创建，所以我们一般不会单独去创建一个用户，而是授权创建一块完成。
-
priv_type 授权类型
- SELECT
- INSERT
- UPDATE
- DELETE
- CREATE
- DROP
- INDEX
- ALTER
- SHOW DATABASES
- CREATE TEMPORARY TABLES
- LOCK TABLES
- CREATE VIEW
- SHOW VIEW
- CREATE USER
- ALL PRIVILEGES 或 ALL -
object_type 授权对象
- TABLE
- FUNCTION
- PROCEDURE -
priv_level 授权级别
- *或*.* 表示所有库
- db_name.* 表示指定库中的所有表
- db_name.tbl_name 指定库中的指定表
- tbl_name 表示当前库的表
- db_name.routine_name 表示指定库的函数,存储过程,触发器 -
WITH GRANT OPTION
- MAX_QUERIES_PER_HOUR count
- MAX_UPDATES_PER_HOUR count
- MAX_CONNECTIONS_PER_HOUR count
- MAX_USER_CONNECTIONS count
MariaDB [school]> GRANT SELECT(stuid,name) ON TABLE school.students TO admin@'%' IDENTIFIED BY 'admin'; #把students表的stuid和name字段的查询权限授权于admin@'%'用户
MariaDB [school]> FLUSH PRIVILEGES; #刷新授权表
2、查询授权
MariaDB [school]> SHOW GRANTS FOR admin@'%'\G #查看指定用户的权限
*************************** 1. row ***************************
Grants for admin@%: GRANT USAGE ON *.* TO 'admin'@'%' IDENTIFIED BY PASSWORD '*4ACFE3202A5FF5CF467898FC58AAB1D615029441'
*************************** 2. row ***************************
Grants for admin@%: GRANT SELECT (stuid, name) ON `school`.`students` TO 'admin'@'%'
[root@working ~]# mysql -uadmin -padmin -h192.168.0.7
MariaDB [(none)]> SHOW GRANTS FOR CURRENT_USER()\G #查询自己的权限
*************************** 1. row ***************************
Grants for admin@%: GRANT USAGE ON *.* TO 'admin'@'%' IDENTIFIED BY PASSWORD '*4ACFE3202A5FF5CF467898FC58AAB1D615029441'
*************************** 2. row ***************************
Grants for admin@%: GRANT SELECT (stuid, name) ON `school`.`students` TO 'admin'@'%'
3、收回授权
MariaDB [school]> REVOKE SELECT(stuid) ON school.students FROM admin@'%'; #收回admin@'%'用户对stuid字段的查询权限