我本来只是为了搭建简单的LAMP环境，亲自动手，却发现有这么多的问题会发生。(by default7#zbphp.com)

很多地方给的安装Mysql的提示是通过yum一键安装。shell命令如下：

yum install mysql

yum install mysql-server

yum install mysql-devel

但是，这个命令安装的mysql版本很旧，5.1.0x版本的，官网的Mysql已经是 5.6.x版本了。太旧了，记得08年的时候就出了 5.1的版本了。

坚持安装最新版本的，在MYSQL官网下载rpm-.tar安装包，300MB左右。linux64。

[root@localhost mysqlinstall]# ls 
MySQL-client-5.6.19-1.linux_glibc2.5.x86_64.rpm
MySQL-devel-5.6.19-1.linux_glibc2.5.x86_64.rpm
MySQL-embedded-5.6.19-1.linux_glibc2.5.x86_64.rpm
MySQL-server-5.6.19-1.linux_glibc2.5.x86_64.rpm
MySQL-shared-5.6.19-1.linux_glibc2.5.x86_64.rpm
MySQL-shared-compat-5.6.19-1.linux_glibc2.5.x86_64.rpm
MySQL-test-5.6.19-1.linux_glibc2.5.x86_64.rpm
[root@localhost mysqlinstall]# pwd
/home/default7@zbphp.com/Downloads/mysqlinstall
[root@localhost mysqlinstall]# 

但是按照网上（CSDN博客、blogcn博客）一步步提示来安装但是总是各种问题，各种问题，无法运行。

最后尝试了很多遍终于安装成功，正常运行：

[root@localhost /]# yum remove mysql
Loaded plugins: fastestmirror, refresh-packagekit, security
Setting up Remove Process
No Match for argument: mysql
Loading mirror speeds from cached hostfile
 * base: mirrors.163.com
 * extras: mirrors.163.com
 * updates: mirrors.163.com
Package(s) mysql available, but not installed.
No Packages marked for removal
[root@localhost /]# yum remove mysql-server
Loaded plugins: fastestmirror, refresh-packagekit, security
Setting up Remove Process
Resolving Dependencies
--> Running transaction check
---> Package MySQL-server.x86_64 0:5.6.19-1.linux_glibc2.5 will be erased
--> Finished Dependency Resolution

Dependencies Resolved

================================================================================
 Package          Arch       Version                        Repository     Size
================================================================================
Removing:
 MySQL-server     x86_64     5.6.19-1.linux_glibc2.5        installed     248 M

Transaction Summary
================================================================================
Remove        1 Package(s)

Installed size: 248 M
Is this ok [y/N]: y
Downloading Packages:
Running rpm_check_debug
Running Transaction Test
Transaction Test Succeeded
Running Transaction
  Erasing    : MySQL-server-5.6.19-1.linux_glibc2.5.x86_64                  1/1 
  Verifying  : MySQL-server-5.6.19-1.linux_glibc2.5.x86_64                  1/1 

Removed:
  MySQL-server.x86_64 0:5.6.19-1.linux_glibc2.5                                 

Complete!
[root@localhost /]# yum remove MySQL-*
Loaded plugins: fastestmirror, refresh-packagekit, security
Setting up Remove Process
Resolving Dependencies
--> Running transaction check
---> Package MySQL-devel.x86_64 0:5.6.19-1.linux_glibc2.5 will be erased
---> Package MySQL-shared.x86_64 0:5.6.19-1.linux_glibc2.5 will be erased
---> Package MySQL-shared-compat.x86_64 0:5.6.19-1.linux_glibc2.5 will be erased
--> Processing Dependency: libmysqlclient.so.16()(64bit) for package: perl-DBD-MySQL-4.013-3.el6.x86_64
--> Processing Dependency: libmysqlclient.so.16(libmysqlclient_16)(64bit) for package: perl-DBD-MySQL-4.013-3.el6.x86_64
--> Running transaction check
---> Package perl-DBD-MySQL.x86_64 0:4.013-3.el6 will be erased
--> Finished Dependency Resolution

Dependencies Resolved

================================================================================
 Package             Arch   Version                 Repository             Size
================================================================================
Removing:
 MySQL-devel         x86_64 5.6.19-1.linux_glibc2.5 installed              17 M
 MySQL-shared        x86_64 5.6.19-1.linux_glibc2.5 @/MySQL-shared-5.6.19-1.linux_glibc2.5.x86_64
                                                                          7.8 M
 MySQL-shared-compat x86_64 5.6.19-1.linux_glibc2.5 @/MySQL-shared-compat-5.6.19-1.linux_glibc2.5.x86_64
                                                                           11 M
Removing for dependencies:
 perl-DBD-MySQL      x86_64 4.013-3.el6             @base                 338 k

Transaction Summary
================================================================================
Remove        4 Package(s)

Installed size: 36 M
Is this ok [y/N]: y
Downloading Packages:
Running rpm_check_debug
Running Transaction Test
Transaction Test Succeeded
Running Transaction
  Erasing    : MySQL-devel-5.6.19-1.linux_glibc2.5.x86_64                   1/4 
  Erasing    : perl-DBD-MySQL-4.013-3.el6.x86_64                            2/4 
  Erasing    : MySQL-shared-compat-5.6.19-1.linux_glibc2.5.x86_64           3/4 
  Erasing    : MySQL-shared-5.6.19-1.linux_glibc2.5.x86_64                  4/4 
  Verifying  : MySQL-shared-compat-5.6.19-1.linux_glibc2.5.x86_64           1/4 
  Verifying  : MySQL-devel-5.6.19-1.linux_glibc2.5.x86_64                   2/4 
  Verifying  : MySQL-shared-5.6.19-1.linux_glibc2.5.x86_64                  3/4 
  Verifying  : perl-DBD-MySQL-4.013-3.el6.x86_64                            4/4 

Removed:
  MySQL-devel.x86_64 0:5.6.19-1.linux_glibc2.5                                  
  MySQL-shared.x86_64 0:5.6.19-1.linux_glibc2.5                                 
  MySQL-shared-compat.x86_64 0:5.6.19-1.linux_glibc2.5                          

Dependency Removed:
  perl-DBD-MySQL.x86_64 0:4.013-3.el6                                           

Complete!
[root@localhost /]# yum remove MySQL-*
Loaded plugins: fastestmirror, refresh-packagekit, security
Setting up Remove Process
No Match for argument: MySQL-*
Loading mirror speeds from cached hostfile
 * base: mirrors.163.com
 * extras: mirrors.163.com
 * updates: mirrors.163.com
Package(s) MySQL-* available, but not installed.
No Packages marked for removal
[root@localhost /]# whereis mysql
mysql: /usr/lib64/mysql
[root@localhost /]# which mysql
/usr/bin/which: no mysql in (/usr/local/bin:/usr/bin:/bin:/usr/local/sbin:/usr/sbin:/sbin:/home/default7/bin)
[root@localhost /]# yum remove MySQL-shared
Loaded plugins: fastestmirror, refresh-packagekit, security
Setting up Remove Process
No Match for argument: MySQL-shared
Loading mirror speeds from cached hostfile
 * base: mirrors.163.com
 * extras: mirrors.163.com
 * updates: mirrors.163.com
No Packages marked for removal
[root@localhost /]# whereis mysql
mysql: /usr/lib64/mysql
[root@localhost /]# which mysql
/usr/bin/which: no mysql in (/usr/local/bin:/usr/bin:/bin:/usr/local/sbin:/usr/sbin:/sbin:/home/default7/bin)
[root@localhost /]# yum remove MySQL-test
Loaded plugins: fastestmirror, refresh-packagekit, security
Setting up Remove Process
No Match for argument: MySQL-test
Loading mirror speeds from cached hostfile
 * base: mirrors.btte.net
 * extras: mirrors.btte.net
 * updates: mirrors.btte.net
Package(s) MySQL-test available, but not installed.
No Packages marked for removal
[root@localhost /]# clear

其实我一直不断的重新安装，总是问题，无法启动或者报错，原因在与第一次安装步骤不正确，然后接下来不断的重装。

但是并没有彻底卸载干净。rpm -e Mysql 这个似乎区分大小写，而我一开始直接删除文件夹来卸载，后来用 rpm -e -nodeps  mysql来卸载，但是还是有残留。

最后是用的yum remove mysql ,mysql-server,mysql-shared 来卸载，为了卸载干净，之后，将所有文件夹中有mysql的删除掉。然后再重新安装。

[root@localhost mysqlinstall]# ls
MySQL-client-5.6.19-1.linux_glibc2.5.x86_64.rpm
MySQL-devel-5.6.19-1.linux_glibc2.5.x86_64.rpm
MySQL-embedded-5.6.19-1.linux_glibc2.5.x86_64.rpm
MySQL-server-5.6.19-1.linux_glibc2.5.x86_64.rpm
MySQL-shared-5.6.19-1.linux_glibc2.5.x86_64.rpm
MySQL-shared-compat-5.6.19-1.linux_glibc2.5.x86_64.rpm
MySQL-test-5.6.19-1.linux_glibc2.5.x86_64.rpm
[root@localhost mysqlinstall]# rpm -ivh MySQL-server-*.rpm
Preparing...                ########################################### [100%]
   1:MySQL-server           ########################################### [100%]
[root@localhost mysqlinstall]# rpm -ivh MySQL-client-*.rpm
Preparing...                ########################################### [100%]
   1:MySQL-client           ########################################### [100%]
[root@localhost mysqlinstall]# rpm -ivh MySQL-devel-*.rpm
Preparing...                ########################################### [100%]
   1:MySQL-devel            ########################################### [100%]
[root@localhost mysqlinstall]# service mysql status
 ERROR! MySQL is not running
[root@localhost mysqlinstall]# service mysql start
Starting MySQL.. SUCCESS! 

修改设置密码，原始密码在/root/这个文件夹里面，ls -a可以看到一个mysql的文件，里面有原始密码：

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


mysql> select user();
ERROR 1820 (HY000): You must SET PASSWORD before executing this statement
mysql> set password=password('zbphp.com');
Query OK, 0 rows affected (0.00 sec)

mysql> show user();
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'user()' at line 1
mysql> select user();
+----------------+
| user()         |
+----------------+
| root@localhost |
+----------------+
1 row in set (0.00 sec)

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| test               |
+--------------------+
4 rows in set (0.01 sec)

mysql> select version();
+-----------+
| version() |
+-----------+
| 5.6.19    |
+-----------+
1 row in set (0.00 sec)

mysql>