(转)MySQL增加用户
创建用户:
命令:

CREATE USER 'username'@'host' IDENTIFIED BY 'password';

说明:username – 你将创建的用户名, host – 指定该用户在哪个主机上可以登陆,如果是本地用户可用localhost,  如果想让该用户可以从任意远程主机登陆,可以使用通配符%. password –  该用户的登陆密码,密码可以为空,如果为空则该用户可以不需要密码登陆服务器.

CREATE USER 'dog'@'localhost' IDENTIFIED BY '123456'; 
CREATE USER 'pig'@'192.168.1.101_' IDENDIFIED BY '123456'; 
CREATE USER 'pig'@'%' IDENTIFIED BY '123456'; 
CREATE USER 'pig'@'%' IDENTIFIED BY ''; 
CREATE USER 'pig'@'%';

授权:
命令:

GRANT privileges ON databasename.tablename TO 'username'@'host'

说明: privileges – 用户的操作权限,如SELECT , INSERT , UPDATE  等(详细列表见该文最后面).如果要授予所的权限则使用ALL.;databasename –  数据库名,tablename-表名,如果要授予该用户对所有数据库和表的相应操作权限则可用*表示, 如*.*.
例子:

GRANT SELECT, INSERT ON test.user TO 'pig'@'%'; 
GRANT ALL ON *.* TO 'pig'@'%';

注意:用以上命令授权的用户不能给其它用户授权,如果想让该用户可以授权,用以下命令:
GRANT privileges ON databasename.tablename TO 'username'@'host' WITH GRANT OPTION；
设置与更改用户密码
命令:

SET PASSWORD FOR 'username'@'host' = PASSWORD('newpassword');

如果是当前登陆用户用

SET PASSWORD = PASSWORD("newpassword");

撤销用户权限
命令:

REVOKE privilege ON databasename.tablename FROM 'username'@'host';

说明: privilege, databasename, tablename – 同授权部分.
例子

REVOKE SELECT ON *.* FROM 'pig'@'%';

注意: 假如你在给用户’pig’@'%’授权的时候是这样的(或类似的):GRANT SELECT ON test.user TO  ‘pig’@'%’, 则在使用REVOKE SELECT ON *.* FROM  ‘pig’@'%’;命令并不能撤销该用户对test数据库中user表的SELECT 操作.相反,如果授权使用的是GRANT SELECT ON  *.* TO ‘pig’@'%’;则REVOKE SELECT ON test.user FROM  ‘pig’@'%’;命令也不能撤销该用户对test数据库中user表的Select 权限.
具体信息可以用命令SHOW GRANTS FOR ‘pig’@'%’; 查看.
删除用户
命令:

DROP USER ‘username’@'host’;

一个典型的数据库建表, 建用户过程:

##创建用于localhost连接的用户并指定密码 
mysql> create user 'pcom'@'localhost' identified by 'aaa7B2249'; 
Query OK, 0 rows affected (0.00 sec) 
     
##创建数据库 
mysql> create database pcom default character set utf8 collate utf8_bin; 
Query OK, 1 row affected (0.00 sec) 
     
##给本地用户授权, 这里不需要指定密码 
mysql> grant all on pcom.* to 'pcom'@'localhost'; 
Query OK, 0 rows affected (0.00 sec) 
     
##给其他IP地址下的用户授权, 注意: 这里必须指定密码, 否则就可以无密码访问 
mysql> grant all on pcom.* to 'pcom'@'192.168.0.0/255.255.0.0' identified by 'aaa7B2249'; 
Query OK, 0 rows affected (0.00 sec) 
     
##同理 
mysql> grant all on pcom.* to 'pcom'@'172.20.0.0/255.255.0.0' identified by 'aaa7B2249'; 
Query OK, 0 rows affected (0.00 sec) 
     
Done!

##刷新系统权限表。 
mysql> flush privileges;

附表:在MySQL中的操作权限

ALTER
## Allows use of ALTER TABLE. 
    
ALTER ROUTINE 
## Alters or drops stored routines. 
    
CREATE
## Allows use of CREATE TABLE. 
    
CREATE ROUTINE 
## Creates stored routines. 
    
CREATE TEMPORARY TABLE
## Allows use of CREATE TEMPORARY TABLE. 
    
CREATE USER
## Allows use of CREATE USER, DROP USER, RENAME USER, and REVOKE ALL  PRIVILEGES. 
    
CREATE VIEW
## Allows use of CREATE VIEW. 
    
DELETE
## Allows use of DELETE. 
    
DROP
## Allows use of DROP TABLE. 
    
EXECUTE
## Allows the user to run stored routines. 
    
FILE 
## Allows use of SELECT… INTO OUTFILE and LOAD DATA INFILE. 
    
INDEX
## Allows use of CREATE INDEX and DROP INDEX. 
    
INSERT
## Allows use of INSERT. 
    
LOCK TABLES 
## Allows use of LOCK TABLES on tables for which the user also has SELECT privileges. 
    
PROCESS 
## Allows use of SHOW FULL PROCESSLIST. 
    
RELOAD 
## Allows use of FLUSH. 
    
REPLICATION 
## Allows the user to ask where slave or master 
    
CLIENT 
## servers are. 
    
REPLICATION SL