MySQL 默认有个root用户，但是这个用户权限太大，一般只在管理数据库时候才用。如果在项目中要连接 MySQL 数据库，则建议新建一个权限较小的用户来连接。

在 MySQL 命令行模式下输入如下命令可以为 MySQL 创建一个新用户：

新用户创建完成，但是此刻如果以此用户登陆的话，会报错，因为我们还没有为这个用户分配相应权限，分配权限的命令如下：

授予username用户在所有数据库上的所有权限。

如果此时发现刚刚给的权限太大了，如果我们只是想授予它在某个数据库上的权限，那么需要切换到root 用户撤销刚才的权限，重新授权：

甚至还可以指定该用户只能执行 select 和 update 命令：

这样一来，再次以username登陆 MySQL，只有wordpress数据库是对其可见的，并且如果你只授权它select权限，那么它就不能执行delete 语句。

另外每当调整权限后，通常需要执行以下语句刷新权限：

删除刚才创建的用户：

仔细上面几个命令，可以发现不管是授权，还是撤销授权，都要指定响应的host(即 @ 符号后面的内容)，因为以上及格命令实际上都是在操作mysql 数据库中的user表，可以用如下命令查看相应用户及对应的host:

MySQL Study之--MySQL用户及权限管理MySQL服务器通过MySQL权限表来控制用户对数据库的访问，MySQL权限表存放在mysql数据库里，由mysql_install_db脚本初始化。这些MySQL权限表分别user，db，table_priv，columns_priv和host。下面分别介绍一下这些表的结构和内容：user权限表：记录允许连接到服务器的用户帐号信息，里面的权限是全局级的。db权限表：记录各个帐号在各个数据库上的操作权限。table_priv权限表：记录数据表级的操作权限。columns_priv权限表：记录数据列级的操作权限。host权限表：配合db权限表对给定主机上数据库级操作权限作更细致的控制。这个权限表不受GRANT和REVOKE语句的影响。案例分析：一、创建用户并授权(root用户)[root@mysrv ~]# mysql -u root -poraclemysql> select version()\g+-------------------------------------------+| version() |+-------------------------------------------+| 5.6.25-enterprise-commercial-advanced-log |+-------------------------------------------+1 row in set (0.00 sec)mysql> show databases;+--------------------+| Database |+--------------------+| information_schema || mysql || performance_schema || prod || test |+--------------------+5 rows in set (0.01 sec)1、建立tom用户并授权(特权管理用户)mysql> grant all on prod.* to 'tom'@'%' identified by 'tom' with grant option;Query OK, 0 rows affected (0.00 sec)查看用户创建是否成功：mysql> select user,host from user ;

查看tom用户的授权：mysql> show grants for tom;+----------------------------------------------------------------------------------------------------+| Grants for tom@% |+----------------------------------------------------------------------------------------------------+| GRANT USAGE ON *.* TO 'tom'@'%' IDENTIFIED BY PASSWORD '*71FF744436C7EA1B954F6276121DB5D2BF68FC07' || GRANT ALL PRIVILEGES ON `prod`.* TO 'tom'@'%' WITH GRANT OPTION |+----------------------------------------------------------------------------------------------------+GRANT 语法:GRANT privileges (columns)ON whatTO 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。tom@'%' 表示任何地址，默认可以省略。还可以是 "tom@192.168.1.%"、"tom@%.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。2、我们用 root 再创建几个用户，然后由 test 数据库的管理员tom为他们分配权限。mysql> create user 'tom1' identified by 'tom1' ,'tom2' identified by 'tom2';Query OK, 0 rows affected (0.00 sec)mysql> select user,host from user ;

root用户退出，tom登陆，并授权用户访问prod库[root@mysrv ~]# mysql -u tom -ptomERROR 1045 (28000): Access denied for user 'tom'@'localhost' (using password: YES)tom用户竟不能登陆！！！再对tom用户授权：mysql> grant all on prod.* to 'tom'@'localhost' identified by 'tom' with grant option;;Query OK, 0 rows affected (0.00 sec)mysql> show grants for tom;+----------------------------------------------------------------------------------------------------+| Grants for tom@% |+----------------------------------------------------------------------------------------------------+| GRANT USAGE ON *.* TO 'tom'@'%' IDENTIFIED BY PASSWORD '*71FF744436C7EA1B954F6276121DB5D2BF68FC07' || GRANT ALL PRIVILEGES ON `prod`.* TO 'tom'@'%' WITH GRANT OPTION |+----------------------------------------------------------------------------------------------------+2 rows in set (0.00 sec)mysql> use mysql;Database changedmysql> select user,host from user ;

tom登陆：[root@mysrv ~]# mysql -u tom -ptom prodmysql> select database();+------------+| database() |+------------+| prod |+------------+1 row in set (0.01 sec)mysql> select current_user();+----------------+| current_user() |+----------------+| tom@localhost |+----------------+1 row in set (0.00 sec)创建表：mysql> show tables;+----------------+| Tables_in_prod |+----------------+| t1 |+----------------+1 row in set (0.00 sec)mysql> create table t2 as select * from t1;Query OK, 3 rows affected (0.15 sec)Records: 3 Duplicates: 0 Warnings: 0查看表信息：mysql> desc t2;+-------+-------------+------+-----+---------+-------+| Field | Type | Null | Key | Default | Extra |+-------+-------------+------+-----+---------+-------+| id | int(11) | YES | | NULL | || name | varchar(10) | YES | | NULL | |+-------+-------------+------+-----+---------+-------+2 rows in set (0.01 sec)mysql> show create table t2;+-------+---------------------------------------------------------------------------------------------------------------------------+| Table | Create Table |+-------+---------------------------------------------------------------------------------------------------------------------------+| t2 | CREATE TABLE `t2` (`id` int(11) DEFAULT NULL,`name` varchar(10) DEFAULT NULL) ENGINE=InnoDB DEFAULT CHARSET=latin1 |+-------+---------------------------------------------------------------------------------------------------------------------------+1 row in set (0.01 sec)mysql> show create table t2\G;*************************** 1. row ***************************Table: t2Create Table: CREATE TABLE `t2` (`id` int(11) DEFAULT NULL,`name` varchar(10) DEFAULT NULL) ENGINE=InnoDB DEFAULT CHARSET=latin11 row in set (0.00 sec)mysql> select * from t2;+------+-------+| id | name |+------+-------+| 10 | tom || 20 | jerry || 30 | rose |+------+-------+3 rows in set (0.00 sec)3、tom用户为tom1，tom2授权mysql> grant select on prod.* to tom1;Query OK, 0 rows affected (0.00 sec)mysql> grant select on prod.* to tom2;Query OK, 0 rows affected (0.02 sec)mysql> grant insert,update on prod.* to tom2;Query OK, 0 rows affected (0.00 sec)tom2登陆(从远程登陆)：C:\Users\Administrator>mysql -h 192.168.8.240 -utom2 -ptom2mysql> select database();+------------+| database() |+------------+| NULL |+------------+1 row in set (0.00 sec)mysql> use prod;Database changedmysql> select database();+------------+| database() |+------------+| prod |+------------+1 row in set (0.00 sec)mysql> select current_user();+----------------+| current_user() |+----------------+| tom2@% |+----------------+1 row in set (0.00 sec)mysql> show grants for tom2;+------------------------------------------------------------------+| Grants for tom2@% |+------------------------------------------------------------------+| GRANT USAGE ON *.* TO 'tom2'@'%' IDENTIFIED BY PASSWORD || GRANT SELECT, INSERT, UPDATE ON `prod`.* TO 'tom2'@'%' |+------------------------------------------------------------------+2 rows in set (0.00 sec)mysql> show tables;+----------------+| Tables_in_prod |+----------------+| t1 || t2 |+----------------+2 rows in set (0.00 sec)mysql> select * from t1;+------+-------+| id | name |+------+-------+| 10 | tom || 20 | jerry || 30 | rose |+------+-------+3 rows in set (0.00 sec)mysql> select * from t2;+------+-------+| id | name |+------+-------+| 10 | tom || 20 | jerry || 30 | rose |+------+-------+3 rows in set (0.00 sec)mysql> insert into t1 values (40,'john');Query OK, 1 row affected (0.00 sec)mysql> commit;Query OK, 0 rows affected (0.09 sec)mysql> select * from t1;+------+-------+| id | name |+------+-------+| 10 | tom || 20 | jerry || 30 | rose || 40 | john |+------+-------+4 rows in set (0.00 sec)mysql> update t1 set name='ellen' where id=40;Query OK, 1 row affected (0.01 sec)Rows matched: 1 Changed: 1 Warnings: 0mysql> select * from t1;+------+-------+| id | name |+------+-------+| 10 | tom || 20 | jerry || 30 | rose || 40 | ellen |+------+-------+4 rows in set (0.00 sec)mysql> delete from t1;ERROR 1142 (42000): DELETE command denied to user 'tom2'@'192.168.8.254' for table 't1'mysql> commit;Query OK, 0 rows affected (0.05 sec)mysql> select * from t1;+------+-------+| id | name |+------+-------+| 10 | tom || 20 | jerry || 30 | rose || 40 | ellen |+------+-------+4 rows in set (0.00 sec)4、回收tom2的update权限：mysql> revoke update on prod.* from tom2;Query OK, 0 rows affected (0.00 sec)tom2再重新登陆：C:\Users\Administrator>mysql -h 192.168.8.240 -utom2 -ptom2mysql> use prod;Database changedmysql> update t1 set name='lily' where id=10;ERROR 1142 (42000): UPDATE command denied to user 'tom2'@'192.168.8.254' for table 't1'---update失败！二、修改用户口令：1、root用户修改普通用户口令mysql> set password for tom1=password('oracle');Query OK, 0 rows affected (0.01 sec)mysql> flush privileges;Query OK, 0 rows affected (0.00 sec)tom1重新登陆：C:\Users\Administrator>mysql -h 192.168.8.240 -utom1 -ptom1Warning: Using a password on the command line interface can be insecure.ERROR 1045 (28000): Access denied for user 'tom1'@'192.168.8.254' (using password: YES)---旧口令登陆失败！C:\Users\Administrator>mysql -h 192.168.8.240 -utom1 -poraclemysql>2、普通用户修改自己密码：C:\Users\Administrator>mysql -h 192.168.8.240 -utom1 -poraclemysql> set password=password('tom1');Query OK, 0 rows affected (0.00 sec)重新登陆：C:\Users\Administrator>mysql -h 192.168.8.240 -utom1 -ptom1mysql>---新密码登陆成功 ！三、删除用户：1、回收用户所有权限mysql> revoke all on prod.* from tom2;Query OK, 0 rows affected (0.01 sec)2、删除用户mysql> drop user tom2;Query OK, 0 rows affected (0.00 sec)mysql> flush privileges;Query OK, 0 rows affected (0.00 sec)mysql> select user,host from user;

------- 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;删除用户:DROP USER user1;数据库列表:SHOW DATABASES;数据表列表:SHOW TABLES;当前数据库:SELECT DATABASE();当前用户:SELECT USER();数据表结构:DESCRIBE table1;刷新权限:FLUSH PRIVILEGES;grant和revoke可以在几个层次上控制访问权限1，整个服务器，使用 grant ALL 和revoke ALL2，整个数据库，使用on database.*3，特点表，使用on database.table4，特定的列5，特定的存储过程user表中host列的值的意义% 匹配所有主机localhost localhost不会被解析成IP地址，直接通过UNIXsocket连接127.0.0.1 会通过TCP/IP协议连接，并且只能在本机访问；::1 ::1就是兼容支持ipv6的，表示同ipv4的127.0.0.1grant 普通数据用户，查询、插入、更新、删除 数据库中所有表数据的权利。grant select on testdb.* to common_user@’%’grant insert on testdb.* to common_user@’%’grant update on testdb.* to common_user@’%’grant delete on testdb.* to common_user@’%’或者，用一条 MySQL 命令来替代：grant select, insert, update, delete on testdb.* to common_user@’%’grant 数据库开发人员，创建表、索引、视图、存储过程、函数。。。等权限。grant 创建、修改、删除 MySQL 数据表结构权限。grant create on testdb.* to developer@’192.168.0.%’;grant alter on testdb.* to developer@’192.168.0.%’;grant drop on testdb.* to developer@’192.168.0.%’;grant 操作 MySQL 外键权限。grant references on testdb.* to developer@’192.168.0.%’;grant 操作 MySQL 临时表权限。grant create temporary tables on testdb.* to developer@’192.168.0.%’;grant 操作 MySQL 索引权限。grant index on testdb.* to developer@’192.168.0.%’;grant 操作 MySQL 视图、查看视图源代码 权限。grant create view on testdb.* to developer@’192.168.0.%’;grant show view on testdb.* to developer@’192.168.0.%’;grant 操作 MySQL 存储过程、函数 权限。grant create routine on testdb.* to developer@’192.168.0.%’; -- now, can show procedure statusgrant alter routine on testdb.* to developer@’192.168.0.%’; -- now, you can drop a proceduregrant execute on testdb.* to developer@’192.168.0.%’;grant 普通 DBA 管理某个 MySQL 数据库的权限。grant all privileges on testdb to dba@’localhost’其中，关键字 “privileges” 可以省略。grant 高级 DBA 管理 MySQL 中所有数据库的权限。grant all on *.* to dba@’localhost’MySQL grant 权限，分别可以作用在多个层次上。1. grant 作用在整个 MySQL 服务器上：grant select on *.* to dba@localhost; -- dba 可以查询 MySQL 中所有数据库中的表。grant all on *.* to dba@localhost; -- dba 可以管理 MySQL 中的所有数据库2. grant 作用在单个数据库上：grant select on testdb.* to dba@localhost; -- dba 可以查询 testdb 中的表。3. grant 作用在单个数据表上：grant select, insert, update, delete on testdb.orders to dba@localhost;4. grant 作用在表中的列上：grant select(id, se, rank) on testdb.apache_log to dba@localhost;5. grant 作用在存储过程、函数上：grant execute on procedure testdb.pr_add to ’dba’@’localhost’grant execute on function testdb.fn_add to ’dba’@’localhost’注意：修改完权限以后 一定要刷新服务，或者重启服务，刷新服务用：FLUSH PRIVILEGES。