可以用 CREATE USER 或 GRANT 创建用户，后者还同时分配相关权限。而 REVOKE 则用于删除用户权限，DROP USER 删除账户。
$ mysql -u root -p
password:
mysql> create database test; # 创建数据库
Query OK, 1 row affected (0.00 sec)
mysql> show databases;
# 查看数据库是否创建成功
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| test |
+--------------------+
3 rows in set (0.00 sec)
mysql> grant all on test.* to user1@'%' identified by '123456' with grant option; # 创建特权管理用户
Query OK, 0 rows affected (0.00 sec)
mysql> select user,host from mysql.user; # 查看用户创建是否成功
+------------------+-----------+
| user | host |
+------------------+-----------+
| user1 | % |
| root | 127.0.0.1 |
| debian-sys-maint | localhost |
| root | localhost |
| root | server |
+------------------+-----------+
5 rows in set (0.00 sec)
mysql> show grants for user1; # 查看用户权限
+--------------------------------------------------------------------------------------------------+
| Grants for user1@% |
|| GRANT USAGE ON *.* TO 'user1'@'%' IDENTIFIED BY PASSWORD '*6BB...2CA2AD9' |
| GRANT ALL PRIVILEGES ON `test`.* TO 'user1'@'%' WITH GRANT OPTION |
+--------------------------------------------------------------------------------------------------+
2 rows in set (0.00 sec)
GRANT 语法:
GRANT privileges (columns)
ON what
TO user IDENTIFIED BY "password"
WITH GRANT OPTION
权限列表:- ALTER: 修改表和索引。
- CREATE: 创建数据库和表。
- DELETE: 删除表中已有的记录。
- DROP: 抛弃(删除)数据库和表。
- INDEX: 创建或抛弃索引。
- INSERT: 向表中插入新行。
- REFERENCE: 未用。
- SELECT: 检索表中的记录。
- UPDATE: 修改现存表记录。
- FILE: 读或写服务器上的文件。
- PROCESS: 查看服务器中执行的线程信息或杀死线程。
- RELOAD: 重载授权表或清空日志、主机缓存或表缓存。
- SHUTDOWN: 关闭服务器。
- ALL: 所有权限，ALL PRIVILEGES同义词。
- USAGE: 特殊的 "无权限" 权限。
用 户账户包括 "username" 和 "host" 两部分，后者表示该用户被允许从何地接入。user1@'%' 表示任何地址，默认可以省略。还可以是 "user1@192.168.1.%"、"user1@%.abc.com" 等。数据库格式为 db@table，可以是 "test.*" 或 "*.*"，前者表示 test 数据库的所有表，后者表示所有数据库的所有表。
子句 "WITH GRANT OPTION" 表示该用户可以为其他用户分配权限。
我们用 root 再创建几个用户，然后由 test 数据库的管理员 user1 为他们分配权限。
mysql> create user user2 identified by '123456', user3 identified by 'abcd'; Query OK, 0 rows affected (0.00 sec)
mysql> select user, host from mysql.user;
+------------------+-----------+
| user | host |
+------------------+-----------+
| user1 | % |
| user2 | % |
| user3 | % |
| root | 127.0.0.1 |
| debian-sys-maint | localhost |
| root | localhost |
| root | server |
+------------------+-----------+
7 rows in set (0.00 sec)
好了，我们退出改用 user1 登录并针对 test 数据库进行操作。
mysql> quit # 退出
Bye
$ mysql -u user1 -p123456 test # 使用新用户登录
mysql> select database(); # 确认当前工作数据库
+------------+
| database() |
+------------+
| test |
+------------+
1 row in set (0.00 sec)
mysql> select current_user(); # 确认当前工作账户
+----------------+
| current_user() |
+----------------+
| user1@% |
+----------------+
1 row in set (0.00 sec)
继续，创建一个数据表。
mysql> create table table1 # 创建表
-> (
-> name varchar(50),
-> age integer
-> );
Query OK, 0 rows affected (0.02 sec)
mysql> show tables; # 查看表是否创建成功
+----------------+
| Tables_in_test |
+----------------+
| table1 |
+----------------+
1 row in set (0.00 sec)
mysql> describe table1; # 查看表结构
+-------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+-------------+------+-----+---------+-------+
| name | varchar(50) | YES | | NULL | |
| age | int(11) | YES | | NULL | |
+-------+-------------+------+-----+---------+-------+
2 rows in set (0.00 sec)
mysql> insert into table1 values('Tom', 20); # 插入记录
Query OK, 1 row affected (0.00 sec)
mysql> select * from table1; # 查询记录
+------+------+
| name | age |
+------+------+
| Tom | 20 |
+------+------+
1 row in set (0.00 sec)
接下来我们为 user2, user3 分配权限。
mysql> grant select on test.* to user2; # 为 user2 分配 SELECT 权限。
Query OK, 0 rows affected (0.00 sec)
mysql> grant select on test.* to user3; # 为 user3 分配 SELECT 权限。
Query OK, 0 rows affected (0.00 sec)
mysql> grant insert, update on test.* to user2; # 再为 user2 增加 INSERT, UPDATE 权限。
Query OK, 0 rows affected (0.00 sec)
好了，我们退出，切换成 user2 操作看看。
$ mysql -u user2 -p123456
mysql> use test; # 切换工作数据库 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> select database(); # 验证当前工作数据库
+------------+
| database() |
+------------+
| test |
+------------+
1 row in set (0.00 sec)
mysql> select user(); # 验证当前账户
+-----------------+
| user() |
+-----------------+
| user2@localhost |
+-----------------+
1 row in set (0.00 sec)
mysql> show grants for user2; # 查看当前用户权限，显然后来添加的 INSERT, UPDATE 被添加了。
+--------------------------------------------------------------------------------------------------+
| Grants for user2@% |
+--------------------------------------------------------------------------------------------------+
| GRANT USAGE ON *.* TO 'user2'@'%' IDENTIFIED BY PASSWORD '*6BB837....2C9' |
| GRANT SELECT, INSERT, UPDATE ON `test`.* TO 'user2'@'%' |
+--------------------------------------------------------------------------------------------------+
2 rows in set (0.00 sec)
进行操作测试。
mysql> insert into table1 values("Jack", 21); # INSERT 操作成功
Query OK, 1 row affected (0.00 sec)
mysql> update table1 set age=22 where name='Jack'; # UPDATE 操作成功
Query OK, 1 row affected (0.00 sec)
Rows matched: 1 Changed: 1 Warnings: 0
mysql> select * from table1; # SELECT 操作成功
+------+------+
| name | age |
+------+------+
| Tom | 20 |
| Jack | 22 |
+------+------+
2 rows in set (0.00 sec)
mysql> delete from table1 where age=22; # DELETE 操作无权限
ERROR 1142 (42000): DELETE command denied to user 'user2'@'localhost' for table 'table1'
我们切换回 user1 管理账户，移除 user2 的 UPDATE 权限看看。
$ mysql -u user1 -p123456 test
mysql> revoke update on test.* from user2; # 移除 UPDATE 权限
Query OK, 0 rows affected (0.00 sec)
再次切换回 user2。
$ mysql -u user2 -p123456 test
mysql> show grants for user2; # UPDATE 权限被移除
+--------------------------------------------------------------------------------------------------+
| Grants for user2@% |
+--------------------------------------------------------------------------------------------------+
| GRANT USAGE ON *.* TO 'user2'@'%' IDENTIFIED BY PASSWORD '*6B...2AD9' |
| GRANT SELECT, INSERT ON `test`.* TO 'user2'@'%' |
+--------------------------------------------------------------------------------------------------+
2 rows in set (0.00 sec)
mysql> update table1 set age=23 where name='Jack'; # 不在拥有 UPDATE 权限
ERROR 1142 (42000): UPDATE command denied to user 'user2'@'localhost' for table 'table1'
好了，到此我们基本完成了创建用户和分配权限的操作。接下来，我们回到 root 进行修改用户密码和删除用户操作。
$ mysql -u root -p123456
mysql> set password for user3=password('abcabc'); # 修改用户 user3 密码
Query OK, 0 rows affected (0.00 sec)
mysql>flush privileges; # 刷新权限表(通常只在直接修改相关管理数据表后需要该操作)
Query OK, 0 rows affected (0.00 sec)
mysql> revoke all on *.* from user2; # 移除 user2 在所有数据库上的权限
Query OK, 0 rows affected (0.00 sec)
mysql> drop user user2; # 删除 user2 账户
Query OK, 0 rows affected (0.00 sec)
mysql> select user,host from mysql.user; # 验证删除结果
+------------------+-----------+
| user | host |
+------------------+-----------+
| user1 | % |
| user3 | % |
| root | 127.0.0.1 |
| debian-sys-maint | localhost |
| root | localhost |
| root | server |
+------------------+-----------+
6 rows in set (0.00 sec)
用户 user2 无法再次使用。
$ mysql -u user2 -p123456 test
ERROR 1045 (28000): Access denied for user 'user2'@'localhost' (using password: YES)
试试 user3。
$ mysql -u user3 -pabc test # 连接失败！哦，对了，我们修改了密码。
ERROR 1045 (28000): Access denied for user 'user3'@'localhost' (using password: YES)
$
mysql -u user3 -pabcabc test # 新密码成功
mysql> select * from table1; # SELECT 操作成功
+------+------+
| name | age |
+------+------+
| Tom | 20 |
| Jack | 22 |
+------+------+
2 rows in set (0.00 sec)
要修改自己的密码直接执行 "set password = password('new_password');" 即可。
------- 摘要 --------------------------------------
创建用户:GRANT insert, update ON testdb.* TO user1@'%' IDENTIFIED BY 'password' WITH GRANT OPTION;
CREATE USER user2 IDENTIFIED BY 'password';
分配权限:GRANT select ON testdb.* TO user2;
查看权限:SHOW GRANTS FOR user1;
修改密码:SET PASSWORD FOR user1 = PASSWORD('newpwd');
SET PASSWORD = PASSWORD('newpwd');
移除权限:REVOKE all ON *.* FROM user1;
