Mysql安装过程（linux：2.6.18-194.el5，Mysql：）

1、安装
[root@RAC2 mysql]# rpm -ivh MySQL-server-5.6.12-2.rhel5.x86_64.rpm 
Preparing...                ########################################### [100%]
   1:MySQL-server           ########################################### [100%]
[root@RAC2 mysql]# rpm -ivh MySQL-client-5.6.12-2.rhel5.x86_64.rpm 
Preparing...                ########################################### [100%]
   1:MySQL-client           ########################################### [100%]

2、安装完查看默认3306端口没有开
[root@RAC2 mysql]# netstat -nat
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address               Foreign Address             State      
tcp        0      0 0.0.0.0:833                 0.0.0.0:*                   LISTEN      
tcp        0      0 0.0.0.0:111                 0.0.0.0:*                   LISTEN      
tcp        0      0 127.0.0.1:631               0.0.0.0:*                   LISTEN      
tcp        0      0 127.0.0.1:25                0.0.0.0:*                   LISTEN      
tcp        0      0 :::22                       :::*                        LISTEN      
tcp        0      0 ::ffff:192.168.72.5:22      ::ffff:192.168.72.1:63851   ESTABLISHED 
tcp        0      0 ::ffff:192.168.72.5:22      ::ffff:192.168.72.1:62929   ESTABLISHED 

3、将mysql启动
[root@RAC2 init.d]# service mysql start
Starting MySQL..[确定]

4、再次确认端口是打开的
[root@RAC2 init.d]# netstat -nat
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address               Foreign Address             State      
tcp        0      0 0.0.0.0:833                 0.0.0.0:*                   LISTEN      
tcp        0      0 0.0.0.0:111                 0.0.0.0:*                   LISTEN      
tcp        0      0 127.0.0.1:631               0.0.0.0:*                   LISTEN      
tcp        0      0 127.0.0.1:25                0.0.0.0:*                   LISTEN      
tcp        0      0 :::3306                     :::*                        LISTEN      
tcp        0      0 :::22                       :::*                        LISTEN      
tcp        0      0 ::ffff:192.168.72.5:22      ::ffff:192.168.72.1:63851   ESTABLISHED 
tcp        0      0 ::ffff:192.168.72.5:22      ::ffff:192.168.72.1:62929   ESTABLISHED 

5、连接mysql
[root@RAC2 bin]# mysql -u root
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)

在网上查资料，可以这样来解决：
[root@RAC2 bin]# /etc/init.d/mysql stop
Shutting down MySQL..[确定]
[root@RAC2 bin]# mysqld_safe --user=mysql --skip-grant-tables --skip-networking &
[1] 6025
[root@RAC2 bin]# 130716 19:00:36 mysqld_safe Logging to '/var/lib/mysql/RAC2.err'.
130716 19:00:36 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql

[root@RAC2 bin]# mysql -u root mysql
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.6.12 MySQL Community Server (GPL)

Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| test               |
+--------------------+
4 rows in set (0.00 sec)

mysql> use mysql;
Database changed
mysql> show tables;
+---------------------------+
| Tables_in_mysql           |
+---------------------------+
| columns_priv              |
| db                        |
| event                     |
| func                      |
| general_log               |
| help_category             |
| help_keyword              |
| help_relation             |
| help_topic                |
| innodb_index_stats        |
| innodb_table_stats        |
| ndb_binlog_index          |
| plugin                    |
| proc                      |
| procs_priv                |
| proxies_priv              |
| servers                   |
| slave_master_info         |
| slave_relay_log_info      |
| slave_worker_info         |
| slow_log                  |
| tables_priv               |
| time_zone                 |
| time_zone_leap_second     |
| time_zone_name            |
| time_zone_transition      |
| time_zone_transition_type |
| user                      |
+---------------------------+
28 rows in set (0.00 sec)

mysql> desc user;
+------------------------+-----------------------------------+------+-----+---------+-------+
| Field                  | Type                              | Null | Key | Default | Extra |
+------------------------+-----------------------------------+------+-----+---------+-------+
| Host                   | char(60)                          | NO   | PRI |         |       |
| User                   | char(16)                          | NO   | PRI |         |       |
| Password               | char(41)                          | NO   |     |         |       |
| Select_priv            | enum('N','Y')                     | NO   |     | N       |       |
| Insert_priv            | enum('N','Y')                     | NO   |     | N       |       |
| Update_priv            | enum('N','Y')                     | NO   |     | N       |       |
| Delete_priv            | enum('N','Y')                     | NO   |     | N       |       |
| Create_priv            | enum('N','Y')                     | NO   |     | N       |       |
| Drop_priv              | enum('N','Y')                     | NO   |     | N       |       |
| Reload_priv            | enum('N','Y')                     | NO   |     | N       |       |
| Shutdown_priv          | enum('N','Y')                     | NO   |     | N       |       |
| Process_priv           | enum('N','Y')                     | NO   |     | N       |       |
| File_priv              | enum('N','Y')                     | NO   |     | N       |       |
| Grant_priv             | enum('N','Y')                     | NO   |     | N       |       |
| References_priv        | enum('N','Y')                     | NO   |     | N       |       |
| Index_priv             | enum('N','Y')                     | NO   |     | N       |       |
| Alter_priv             | enum('N','Y')                     | NO   |     | N       |       |
| Show_db_priv           | enum('N','Y')                     | NO   |     | N       |       |
| Super_priv             | enum('N','Y')                     | NO   |     | N       |       |
| Create_tmp_table_priv  | enum('N','Y')                     | NO   |     | N       |       |
| Lock_tables_priv       | enum('N','Y')                     | NO   |     | N       |       |
| Execute_priv           | enum('N','Y')                     | NO   |     | N       |       |
| Repl_slave_priv        | enum('N','Y')                     | NO   |     | N       |       |
| Repl_client_priv       | enum('N','Y')                     | NO   |     | N       |       |
| Create_view_priv       | enum('N','Y')                     | NO   |     | N       |       |
| Show_view_priv         | enum('N','Y')                     | NO   |     | N       |       |
| Create_routine_priv    | enum('N','Y')                     | NO   |     | N       |       |
| Alter_routine_priv     | enum('N','Y')                     | NO   |     | N       |       |
| Create_user_priv       | enum('N','Y')                     | NO   |     | N       |       |
| Event_priv             | enum('N','Y')                     | NO   |     | N       |       |
| Trigger_priv           | enum('N','Y')                     | NO   |     | N       |       |
| Create_tablespace_priv | enum('N','Y')                     | NO   |     | N       |       |
| ssl_type               | enum('','ANY','X509','SPECIFIED') | NO   |     |         |       |
| ssl_cipher             | blob                              | NO   |     | NULL    |       |
| x509_issuer            | blob                              | NO   |     | NULL    |       |
| x509_subject           | blob                              | NO   |     | NULL    |       |
| max_questions          | int(11) unsigned                  | NO   |     | 0       |       |
| max_updates            | int(11) unsigned                  | NO   |     | 0       |       |
| max_connections        | int(11) unsigned                  | NO   |     | 0       |       |
| max_user_connections   | int(11) unsigned                  | NO   |     | 0       |       |
| plugin                 | char(64)                          | YES  |     |         |       |
| authentication_string  | text                              | YES  |     | NULL    |       |
| password_expired       | enum('N','Y')                     | NO   |     | N       |       |
+------------------------+-----------------------------------+------+-----+---------+-------+
43 rows in set (0.00 sec)

mysql> select hosr,user,password from user;
ERROR 1054 (42S22): Unknown column 'hosr' in 'field list'
mysql> select host,user,password from user;
+-----------+------+-------------------------------------------+
| host      | user | password                                  |
+-----------+------+-------------------------------------------+
| localhost | root | *34F5F8A5C7F9EA100FB15F7FCF1BC31271C3D43C |
| RAC2      | root | *34F5F8A5C7F9EA100FB15F7FCF1BC31271C3D43C |
| 127.0.0.1 | root | *34F5F8A5C7F9EA100FB15F7FCF1BC31271C3D43C |
| ::1       | root | *34F5F8A5C7F9EA100FB15F7FCF1BC31271C3D43C |
+-----------+------+-------------------------------------------+
4 rows in set (0.00 sec)

mysql> update user set password=password('root123') where user='root' and host='localhost';
Query OK, 1 row affected (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 0

mysql> commit
    -> ;
Query OK, 0 rows affected (0.00 sec)

执行下面这一句，是因为上面使表处于：The MySQL server is running with the --skip-grant-tables option，如果不执行下面这句，即使连上数据库也执行不了操作。
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)

mysql> quit
Bye
[root@RAC2 bin]# /etc/init.d/mysql restart
Shutting down MySQL..130716 19:03:34 mysqld_safe mysqld from pid file /var/lib/mysql/RAC2.pid ended
[确定]
Starting MySQL..[确定]
[1]+  Done                    mysqld_safe --user=mysql --skip-grant-tables --skip-networking
[root@RAC2 bin]# mysql -u root -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.6.12

Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql>
下面这步有点诡异啊~
mysql> use mysql;

ERROR 1820 (HY000): You must SET PASSWORD before executing this statement
mysql> show databases;
ERROR 1820 (HY000): You must SET PASSWORD before executing this statement

mysql> set password=PASSWORD('root123');
Query OK, 0 rows affected (0.00 sec)

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| test               |
+--------------------+
4 rows in set (0.00 sec)