卸载当前的 MySQL
查看当前 MySQL 版本：
代码语言：javascript复制[root@coderknock ~]# mysql -V
mysql Ver 14.14 Distrib 5.1.73, for redhat-linux-gnu (i386) using readline 5.1停止 MySQL 服务
代码语言：javascript复制[root@coderknock ~]# service mysqld stop
Stopping mysqld: [ OK ]备份数据【数据不重要可以忽略】
备份数据库，升级MySQL通常不会丢失数据，但保险起见，我们需要做这一步。输入命令：
代码语言：javascript复制[root@coderknock ~]# mysqldump -u xxx -h xxx -P 3306 -p --all-databases > databases.sql卸载旧版本 MySQL
代码语言：javascript复制[root@coderknock ~]# yum remove mysql mysql-*
Loaded plugins: security
Setting up Remove Process
Resolving Dependencies
--> Running transaction check
---> Package mysql.i686 0:5.1.73-7.el6 will be erased
---> Package mysql-libs.i686 0:5.1.73-7.el6 will be erased
--> Processing Dependency: libmysqlclient.so.16 for package: 2:postfix-2.6.6-6.el6_7.1.i686
--> Processing Dependency: libmysqlclient.so.16 for package: perl-DBD-MySQL-4.013-3.el6.i686
--> Processing Dependency: libmysqlclient.so.16(libmysqlclient_16) for package: 2:postfix-2.6.6-6.el6_7.1.i686
--> Processing Dependency: libmysqlclient.so.16(libmysqlclient_16) for package: perl-DBD-MySQL-4.013-3.el6.i686
--> Processing Dependency: mysql-libs for package: 2:postfix-2.6.6-6.el6_7.1.i686
---> Package mysql-server.i686 0:5.1.73-7.el6 will be erased
--> Running transaction check
---> Package perl-DBD-MySQL.i686 0:4.013-3.el6 will be erased
---> Package postfix.i686 2:2.6.6-6.el6_7.1 will be erased
--> Processing Dependency: /usr/sbin/sendmail for package: cronie-1.4.4-16.el6_8.2.i686
--> Processing Dependency: /usr/sbin/sendmail for package: redhat-lsb-core-4.0-7.el6.centos.i686
--> Running transaction check
---> Package cronie.i686 0:1.4.4-16.el6_8.2 will be erased
--> Processing Dependency: cronie = 1.4.4-16.el6_8.2 for package: cronie-anacron-1.4.4-16.el6_8.2.i686
---> Package redhat-lsb-core.i686 0:4.0-7.el6.centos will be erased
--> Running transaction check
---> Package cronie-anacron.i686 0:1.4.4-16.el6_8.2 will be erased
--> Processing Dependency: /etc/cron.d for package: crontabs-1.10-33.el6.noarch
--> Processing Dependency: /etc/cron.d for package: sysstat-9.0.4-31.el6.i686
--> Restarting Dependency Resolution with new changes.
--> Running transaction check
---> Package crontabs.noarch 0:1.10-33.el6 will be erased
---> Package sysstat.i686 0:9.0.4-31.el6 will be erased
--> Finished Dependency Resolution
Dependencies Resolved
=======================================================================================================================================================================================================
Package Arch Version Repository Size
=======================================================================================================================================================================================================
Removing:
mysql i686 5.1.73-7.el6 @base 2.3 M
mysql-libs i686 5.1.73-7.el6 @base 3.9 M
mysql-server i686 5.1.73-7.el6 @base 24 M
Removing for dependencies:
cronie i686 1.4.4-16.el6_8.2 @updates 169 k
cronie-anacron i686 1.4.4-16.el6_8.2 @updates 38 k
crontabs noarch 1.10-33.el6 @anaconda-CentOS-201311291201.i386/6.5 2.4 k
perl-DBD-MySQL i686 4.013-3.el6 @base 341 k
postfix i686 2:2.6.6-6.el6_7.1 @base 9.3 M
redhat-lsb-core i686 4.0-7.el6.centos @anaconda-CentOS-201311291201.i386/6.5 22 k
sysstat i686 9.0.4-31.el6 @base 804 k
Transaction Summary
=======================================================================================================================================================================================================
Remove 10 Package(s)
Installed size: 41 M
Is this ok [y/N]: y
Downloading Packages:
Running rpm_check_debug
Running Transaction Test
Transaction Test Succeeded
Running Transaction
Erasing : mysql-server-5.1.73-7.el6.i686 1/10
warning: /var/log/mysqld.log saved as /var/log/mysqld.log.rpmsave
Erasing : redhat-lsb-core-4.0-7.el6.centos.i686 2/10
/var/tmp/rpm-tmp.Y5QGjy: line 1: lsb_release: command not found
Erasing : mysql-5.1.73-7.el6.i686 3/10
Erasing : perl-DBD-MySQL-4.013-3.el6.i686 4/10
Erasing : sysstat-9.0.4-31.el6.i686 5/10
Erasing : crontabs-1.10-33.el6.noarch 6/10
Erasing : cronie-anacron-1.4.4-16.el6_8.2.i686 7/10
Erasing : cronie-1.4.4-16.el6_8.2.i686 8/10
Erasing : 2:postfix-2.6.6-6.el6_7.1.i686 9/10
Erasing : mysql-libs-5.1.73-7.el6.i686 10/10
Verifying : redhat-lsb-core-4.0-7.el6.centos.i686 1/10
Verifying : perl-DBD-MySQL-4.013-3.el6.i686 2/10
Verifying : mysql-server-5.1.73-7.el6.i686 3/10
Verifying : crontabs-1.10-33.el6.noarch 4/10
Verifying : sysstat-9.0.4-31.el6.i686 5/10
Verifying : cronie-anacron-1.4.4-16.el6_8.2.i686 6/10
Verifying : cronie-1.4.4-16.el6_8.2.i686 7/10
Verifying : mysql-libs-5.1.73-7.el6.i686 8/10
Verifying : mysql-5.1.73-7.el6.i686 9/10
Verifying : 2:postfix-2.6.6-6.el6_7.1.i686 10/10
Removed:
mysql.i686 0:5.1.73-7.el6 mysql-libs.i686 0:5.1.73-7.el6 mysql-server.i686 0:5.1.73-7.el6
Dependency Removed:
cronie.i686 0:1.4.4-16.el6_8.2 cronie-anacron.i686 0:1.4.4-16.el6_8.2 crontabs.noarch 0:1.10-33.el6 perl-DBD-MySQL.i686 0:4.013-3.el6 postfix.i686 2:2.6.6-6.el6_7.1
redhat-lsb-core.i686 0:4.0-7.el6.centos sysstat.i686 0:9.0.4-31.el6
Complete!这样就卸载完成了，为了保险起见我们检查一下系统中是否还有 MySQL 相关内容没有删除干净
代码语言：javascript复制[root@coderknock ~]# yum list installed | grep mysql
[root@coderknock ~]# 上面的情况是没有未删除部分，如果有的话可通过下面的命令删除：
代码语言：javascript复制[root@coderknock ~]# yum remove mysql－libs下载最新版本的 MySQL
查看系统配置信息选择对应 MySQL 包
代码语言：javascript复制[root@coderknock ~]# uname -r
3.10.104-1.el6.elrepo.i686在浏览器打开 sohu提供的 MySQL 镜像（官网速度太慢）
然后根据自己系统配置选择对应的 rpm 包，右键复制文件链接，我的选择如下：
下载并解压
代码语言：javascript复制[root@coderknock ~]# wget http://mirrors.sohu.com/mysql/MySQL-5.7/mysql-5.7.17-1.el6.i686.rpm-bundle.tar
--2017-01-06 22:46:15-- http://mirrors.sohu.com/mysql/MySQL-5.7/mysql-5.7.17-1.el6.i686.rpm-bundle.tar
Resolving mirrors.sohu.com... 119.188.36.70
Connecting to mirrors.sohu.com|119.188.36.70|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 448163840 (427M) [application/octet-stream]
Saving to: “mysql-5.7.17-1.el6.i686.rpm-bundle.tar”
100%[=============================================================================================================================================================>] 448,163,840 9.98M/s in 45s
2017-01-06 22:47:00 (9.54 MB/s) - “mysql-5.7.17-1.el6.i686.rpm-bundle.tar” saved [448163840/448163840]
[root@coderknock ~]# tar xvf mysql-5.7.17-1.el6.i686.rpm-bundle.tar
mysql-community-libs-compat-5.7.17-1.el6.i686.rpm
mysql-community-client-5.7.17-1.el6.i686.rpm
mysql-community-embedded-devel-5.7.17-1.el6.i686.rpm
mysql-community-devel-5.7.17-1.el6.i686.rpm
mysql-community-common-5.7.17-1.el6.i686.rpm
mysql-community-test-5.7.17-1.el6.i686.rpm
mysql-community-embedded-5.7.17-1.el6.i686.rpm
mysql-community-libs-5.7.17-1.el6.i686.rpm
mysql-community-server-5.7.17-1.el6.i686.rpm安装及配置
安装 rpm 【有依赖关系，请按下面的步骤安装，搜索 [root@coderknock ~]# 可跳过安装日志直接查看相关命令】
代码语言：javascript复制[root@coderknock ~]# yum localinstall mysql-community-common-5.7.17-1.el6.i686.rpm
Loaded plugins: security
Setting up Local Package Process
Examining mysql-community-common-5.7.17-1.el6.i686.rpm: mysql-community-common-5.7.17-1.el6.i686
Marking mysql-community-common-5.7.17-1.el6.i686.rpm to be installed
Resolving Dependencies
--> Running transaction check
---> Package mysql-community-common.i686 0:5.7.17-1.el6 will be installed
--> Finished Dependency Resolution
Dependencies Resolved
=======================================================================================================================================================================================================
Package Arch Version Repository Size
=======================================================================================================================================================================================================
Installing:
mysql-community-common i686 5.7.17-1.el6 /mysql-community-common-5.7.17-1.el6.i686 2.5 M
Transaction Summary
=======================================================================================================================================================================================================
Install 1 Package(s)
Total size: 2.5 M
Installed size: 2.5 M
Is this ok [y/N]: y
Downloading Packages:
Running rpm_check_debug
Running Transaction Test
Transaction Test Succeeded
Running Transaction
Installing : mysql-community-common-5.7.17-1.el6.i686 1/1
Verifying : mysql-community-common-5.7.17-1.el6.i686 1/1
Installed:
mysql-community-common.i686 0:5.7.17-1.el6
Complete!
[root@coderknock ~]# yum localinstall mysql-community-libs-5.7.17-1.el6.i686.rpm
Loaded plugins: security
Setting up Local Package Process
Examining mysql-community-libs-5.7.17-1.el6.i686.rpm: mysql-community-libs-5.7.17-1.el6.i686
Marking mysql-community-libs-5.7.17-1.el6.i686.rpm to be installed
Resolving Dependencies
--> Running transaction check
---> Package mysql-community-libs.i686 0:5.7.17-1.el6 will be installed
--> Finished Dependency Resolution
Dependencies Resolved
=======================================================================================================================================================================================================
Package Arch Version Repository Size
=======================================================================================================================================================================================================
Installing:
mysql-community-libs i686 5.7.17-1.el6 /mysql-community-libs-5.7.17-1.el6.i686 7.8 M
Transaction Summary
=======================================================================================================================================================================================================
Install 1 Package(s)
Total size: 7.8 M
Installed size: 7.8 M
Is this ok [y/N]: y
Downloading Packages:
Running rpm_check_debug
Running Transaction Test
Transaction Test Succeeded
Running Transaction
Installing : mysql-community-libs-5.7.17-1.el6.i686 1/1
Verifying : mysql-community-libs-5.7.17-1.el6.i686 1/1
Installed:
mysql-community-libs.i686 0:5.7.17-1.el6
Complete!
[root@coderknock ~]# yum localinstall mysql-community-client-5.7.17-1.el6.i686.rpm
Loaded plugins: security
Setting up Local Package Process
Examining mysql-community-client-5.7.17-1.el6.i686.rpm: mysql-community-client-5.7.17-1.el6.i686
Marking mysql-community-client-5.7.17-1.el6.i686.rpm to be installed
Resolving Dependencies
--> Running transaction check
---> Package mysql-community-client.i686 0:5.7.17-1.el6 will be installed
--> Finished Dependency Resolution
Dependencies Resolved
=======================================================================================================================================================================================================
Package Arch Version Repository Size
=======================================================================================================================================================================================================
Installing:
mysql-community-client i686 5.7.17-1.el6 /mysql-community-client-5.7.17-1.el6.i686 87 M
Transaction Summary
=======================================================================================================================================================================================================
Install 1 Package(s)
Total size: 87 M
Installed size: 87 M
Is this ok [y/N]: ^[[A^Hy
Is this ok [y/N]: y
Downloading Packages:
Running rpm_check_debug
Running Transaction Test
Transaction Test Succeeded
Running Transaction
Installing : mysql-community-client-5.7.17-1.el6.i686 1/1
Verifying : mysql-community-client-5.7.17-1.el6.i686 1/1
Installed:
mysql-community-client.i686 0:5.7.17-1.el6
Complete!
[root@coderknock ~]# yum localinstall mysql-community-server-5.7.17-1.el6.i686.rpm
Loaded plugins: security
Setting up Local Package Process
Examining mysql-community-server-5.7.17-1.el6.i686.rpm: mysql-community-server-5.7.17-1.el6.i686
Marking mysql-community-server-5.7.17-1.el6.i686.rpm to be installed
Resolving Dependencies
--> Running transaction check
---> Package mysql-community-server.i686 0:5.7.17-1.el6 will be installed
--> Finished Dependency Resolution
Dependencies Resolved
=======================================================================================================================================================================================================
Package Arch Version Repository Size
=======================================================================================================================================================================================================
Installing:
mysql-community-server i686 5.7.17-1.el6 /mysql-community-server-5.7.17-1.el6.i686 695 M
Transaction Summary
=======================================================================================================================================================================================================
Install 1 Package(s)
Total size: 695 M
Installed size: 695 M
Is this ok [y/N]: y
Downloading Packages:
Running rpm_check_debug
Running Transaction Test
Transaction Test Succeeded
Running Transaction
Installing : mysql-community-server-5.7.17-1.el6.i686 1/1
Verifying : mysql-community-server-5.7.17-1.el6.i686 1/1
Installed:
mysql-community-server.i686 0:5.7.17-1.el6
Complete!配置
查看版本
代码语言：javascript复制[root@coderknock ~]# mysql -V
mysql Ver 14.14 Distrib 5.7.17, for Linux (i686) using EditLine wrapper启动 MySQL
代码语言：javascript复制[root@coderknock ~]# service mysqld start
MySQL Daemon failed to start.
Starting mysqld: [FAILED]上面的情况说明启动失败，这是因为经过上面的步骤，MySQL 最新版已经安装到我们的系统了，但这是还没有初始化数据，所以导致无法启动。
初始化数据库
代码语言：javascript复制[root@coderknock ~]# mysqld --initialize如果遇到错误如下：
代码语言：javascript复制2017-01-06T14:53:08.889803Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2017-01-06T14:53:08.892190Z 0 [ERROR] --initialize specified but the data directory has files in it. Aborting.
2017-01-06T14:53:08.892475Z 0 [ERROR] Aborting可以运行以下命令【无需再执行 mysqld --initialize】：
[root@coderknock ~]# rm -rf /var/lib/mysql
[root@coderknock ~]# service mysqld start
Initializing MySQL database: [ OK ]
Installing validate password plugin: [ OK ]
Starting mysqld: [ OK ]这样我们就启动了 MySQL 服务
MySQL 无法登陆的解决办法
登录时我遇到了一些问题：
代码语言：javascript复制[root@coderknock ~]# mysql -u root -p
Enter password:
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)这是因较新版本的 MySQL 因为安全的考虑，会设置默认密码
代码语言：javascript复制[root@coderknock ~]# grep 'temporary password' /var/log/mysqld.log
2017-01-06T14:53:33.490540Z 1 [Note] A temporary password is generated for root@localhost: Ei(GLix_p6/1这样就找到了密码，如果上面方法不可行可以看看是否有 /root/.mysql_secret 文件
或者通过以下方法直接修改密码：
代码语言：javascript复制[root@coderknock ~]# service mysqld stop
Stopping mysqld: [ OK ]
[root@coderknock ~]# mysqld_safe --user=mysql --skip-grant-tables --skip-networking &
[1] 14208
[root@coderknock ~]# 2017-01-06T15:02:18.663496Z mysqld_safe Logging to '/var/log/mysqld.log'.
2017-01-06T15:02:18.666764Z mysqld_safe Logging to '/var/log/mysqld.log'.
2017-01-06T15:02:18.693025Z mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql
^C
[root@coderknock ~]# 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 3
Server version: 5.7.17 MySQL Community Server (GPL)
Copyright (c) 2000, 2016, 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>update mysql.user set authentication_string=password('你的密码.') where User='root';
Query OK, 1 row affected, 1 warning (0.00 sec)
Rows matched: 1 Changed: 1 Warnings: 1
mysql> flush privileges;
mysql> update mysql.user set Host='%' where User='root'
Query OK, 1 row affected, 1 warning (0.00 sec)
Rows matched: 1 Changed: 1 Warnings: 1
mysql> flush privileges;注意SQL在Linux下要注意大小写，执行之后Query OK, 1 row affected, 1 warning (0.00 sec)，row 之前是1才代表执行成功了。update mysql.user set Host='%' where User='root' 这句是为了别的 IP 的机器也可以登录我们的MySQL，可以按需执行
重置密码
无论是获取到了默认密码还是强行修改了密码。新版 MySQL 在第一次通过密码登录后会无法执行SQL：
代码语言：javascript复制mysql> select host from mysql.user where User='root';
ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.这是因为 MySQL 为了安全会要求修改初始密码。
代码语言：javascript复制mysql> ALTER USER 'root'@'%' IDENTIFIED BY '你的密码';如果遇到ERROR 1819 (HY000): Your password does not satisfy the current policy requirements说明你的密码太简单，需要设置复杂点的密码，有大小写字母、有数字、有标点基本上就可以通过。
注意，如果你没有修改过 root 用户的Host或者修改为非 % 的字符，需要对上面的语句进行对应的修改，例如： ALTER USER ‘root’@’localhost’ IDENTIFIED BY ‘你的密码’
如果遇到ERROR 1290 (HY000): The MySQL server is running with the --skip-grant-tables option so it cannot execute this statement 则需要退出安全模式，正常启动MySQL后登陆再进行以上操作：
mysql> quit
[root@coderknock ~]# ps -ef|grep mysql
root 14208 12686 0 23:02 pts/0 00:00:00 /bin/sh /usr/bin/mysqld_safe --user=mysql --skip-grant-tables --skip-networking
mysql 14381 14208 0 23:02 pts/0 00:00:00 /usr/sbin/mysqld --basedir=/usr --datadir=/var/lib/mysql --plugin-dir=/usr/lib/mysql/plugin --user=mysql --skip-grant-tables --skip-networking --log-error=/var/log/mysqld.log --pid-file=/var/run/mysqld/mysqld.pid --socket=/var/lib/mysql/mysql.sock
root 15148 12686 0 23:23 pts/0 00:00:00 grep mysql
[root@coderknock ~]# kill -9 114208
-bash: kill: (114208) - No such process
[root@coderknock ~]# kill -9 14208
[1] Killed mysqld_safe --user=mysql --skip-grant-tables --skip-networking
[root@coderknock ~]# kill -9 1438
[root@coderknock ~]# service mysqld start
[root@coderknock ~]# mysql -u root mysql如有问题可以留下你的评论，或加入 拿客 中的qq群咨询。
