路由器，交换机密码的设置

允许root远程连接，并开放所有权限(新建一个用户也是使用这个命令)：

允许root从所有机器远程连接：

grant all privileges on *.* to 'root'@'%' identified by 'password';

允许IP为192.168.11*的机器：

grant all privileges on *.* to 'root'@'192.168.11%' identified by '123456';

在5.0.x中, privileges可以省去不写(4.x中未验证过), 比如允许trsids从IP为192.168.11*的机器远程连接trsidsv3数据库, 并在该数据库上有所有权限:

grant all on trsidsv3.* to 'trsids'@'192.168.11%' identified by 'trs123';

列出用户的权限

列出当前连接用户的权限: show grants

列出用户trs在localhost上的权限: show grants for 'trs'@'localhost';

列出当前所有连接

show full processlist;

如何知道当前运行的数据目录和启动目录

mysql> show variables like "%dir%";
+----------------------------+----------------------------------+
| Variable_name              | Value                            |
+----------------------------+----------------------------------+
| basedir                    | /usr/local/                      |
| character_sets_dir         | /usr/local/share/mysql/charsets/ |
| datadir                    | /usr/local/var/                  |
| innodb_data_home_dir       |                                  |
| innodb_log_arch_dir        |                                  |
| innodb_log_group_home_dir  | ./                               |
| innodb_max_dirty_pages_pct | 90                               |
| slave_load_tmpdir          | /tmp/                            |
| tmpdir                     | /tmp/                            |
+----------------------------+----------------------------------+
9 rows in set (0.00 sec)

一台机器上安装有多台运行的mysql访问方式

1. ps -ef | grep mysql

[root@RHEL4-32 ~]# ps -ef | grep mysql
root      3485     1  0 May31 ?        00:00:00 /bin/sh /var/eyou/mysql/bin/mysqld_safe --defaults-file=/var/eyou/mysql/var/my.cnf --user=root

root      3512  3485  0 May31 ?        00:00:00 /var/eyou/mysql/libexec/mysqld --defaults-file=/var/eyou/mysql/var/my.cnf --basedir=/var/eyou/mysql
--datadir=/var/eyou/mysql/var --user=root --pid-file=/var/eyou/mysql/var/RHEL4-32.pid --skip-locking --port=3306 --socket=/tmp/mysql.sock

root      3916     1  0 May31 ?        00:00:00 /bin/sh /usr/local/mysql/bin/mysqld_safe --defaults-file=/usr/local/mysql/my-medium.cnf --user=root

root      4511  3916  0 May31 ?        00:00:02 /usr/local/libexec/mysqld --defaults-file=/usr/local/mysql/my-medium.cnf --basedir=/usr/local
--datadir=/usr/local/var --user=root --pid-file=/usr/local/var/RHEL4-32.pid --skip-external-locking --port=3356 --socket=/tmp/mysql2.sock

root     22162 22125  0 00:15 pts/3    00:00:00 grep mysql

2. 如果选择端口为3356的mysql，则输入如下命令

mysql -h192.9.200.170 -S/tmp/mysql2.sock -uroot

本文出自 “追忆_zb” 博客，请务必保留此出处http://zhengbin.blog.51cto.com/2989505/1172814