1、添加用户
本机访问权限：
mysql> GRANT ALL PRIVILEGES ON *.* TO 'username'@'localhost'
-> IDENTIFIED BY 'password' WITH GRANT OPTION;
远程访问权限：
mysql> GRANT ALL PRIVILEGES ON *.* TO 'username'@'%'
-> IDENTIFIED BY 'password' WITH GRANT OPTION;
另外还有一种方法是直接Insert INTO user，注意这种方法之后需要 FLUSH PRIVILEGES 让服务器重读授权表。
insert into user(host,user,password,ssl_cipher,x509_issuer,x509_subject)
values(‘localhost’,'xff’,password(‘xff’),”,”,”);
FLUSH PRIVILEGES;
note：1）必须要加上ssl_cipher,x509_issuer,x509_subject三列，以为其默认值不为空（数据库版本为：5.0.51b）
2）FLUSH PRIVILEGES重载授权表，使权限更改生效
3）mysql是通过User表，Db表，Host表，Tables_priv 表，Columns_priv 表这5张表实现用户权限控制，均可以通过直接对这些表的操作以达到对用户的管理
2、删除用户
drop user admin@localhost;（@不加默认为“%”）
3、权限回收
revoke delete on test.* from admin@'localhost';
4、创建用户授权一起实现
grant select,insert,update,delete on *.* to 'admin2′@'%'
identified by ‘admin2′ with grant option;
note：在mysql中，如果@后面的登录范围不同，帐号可以一样
5、限制用户资源
mysql> GRANT ALL ON customer.* TO 'francis'@'localhost'
-> IDENTIFIED BY 'frank'
-> WITH MAX_QUERIES_PER_HOUR 20
-> MAX_UPDATES_PER_HOUR 10
-> MAX_CONNECTIONS_PER_HOUR 5
-> MAX_USER_CONNECTIONS 2;
6、用户密码设置
使用mysqladmin：
shell> mysqladmin -u user_name -h host_name password "newpwd"
或在mysql里执行语句：
mysql> SET PASSWORD FOR 'username'@'%'
= PASSWORD('password');
如果只是更改自己的密码，则：
mysql> SET PASSWORD = PASSWORD(‘password’);
在全局级别使用GRANT USAGE语句(在*.*)来指定某个账户的密码:
mysql> GRANT USAGE ON *.* TO 'username'@'%'
IDENTIFIED BY 'password';
或直接修改MySQL库表：
mysql> UPDATE user SET Password = PASSWORD('bagel')
-> WHERE Host = '%' AND User = 'francis';
mysql> FLUSH PRIVILEGES;
修改root密码：
update mysql.user set password=password(‘passw0rd’) where user=’root’;
FLUSH PRIVILEGES;
7、关于加密
mysql> select PASSWORD('password');
+-------------------------------------------+
| PASSWORD('password') |
+-------------------------------------------+
| *2470C0C06DEE42FD1618BB99005ADCA2EC9D1E19 |
+-------------------------------------------+
1 row in set (0.00 sec)
mysql> select MD5('hello');
+----------------------------------+
| MD5('hello') |
+----------------------------------+
| 5d41402abc4b2a76b9719d911017c592 |
+----------------------------------+
1 row in set (0.00 sec)
mysql> select SHA1('abc');
-> 'a9993e364706816aba3e25717850c26c9cd0d89d'
SHA1()是为字符串算出一个 SHA1 160比特检查和，如RFC 3174 (安全散列算法)中所述。
8、授权精确到列
grant select (cur_url,pre_url) on test.abc to admin@localhost;
