Mysql一个熟悉的概念，一个全新的知识领域。开始我全方位数据库学习之旅。
成都创新互联公司于2013年成立，是专业互联网技术服务公司，拥有项目
网站建设、成都网站设计网站策划，项目实施与项目整合能力。我们以让每一个梦想脱颖而出为使命，1280元黟县做网站,已为上家服务,为黟县各地企业和个人服务,联系电话:13518219792
一切，从安装开始，自己动手每一步。
Linux在安装的过程中，可以勾选Mysql的安装，但是安装的版本是Mysql-5.1.73，版本非常低。必须重新安装，当前最新版本是5.7。但是卸载再安装，明显比空白Linux安装麻烦一点。
下面开始卸载/安装过程。
1. Mysql下载地址
mysql-5.7.22-1.el6.x86_64.rpm-bundle.tar
https://dev.mysql.com/downloads/file/?id=476884
2. 确认OS版本
# more /etc/issue
CentOS release 6.7 (Final)
Kernel \r on an \m# lsb_release -a
LSB Version: :base-4.0-amd64:base-4.0-noarch:core-4.0-amd64:core-4.0-noarch:graphics-4.0-amd64:graphics-4.0-noarch:printing-4.0-amd64:printing-4.0-noarch
Distributor ID: CentOS
Description: CentOS release 6.7 (Final)
Release: 6.7
Codename: Final
3. 根据OS版本，找到需要下载的Mysql版本，右键“将链接另存为”，即可获得下载地址
4. 到Linux下，通过wget下载
wget https://dev.mysql.com/get/Downloads/MySQL-5.7/mysql-community-server-5.7.18-1.el6.x86_64.rpm
下面三个rpm包存在依赖关系，也需要下载
# wget https://cdn.mysql.com//Downloads/MySQL-5.7/mysql-community-common-5.7.18-1.el6.x86_64.rpm
# wget https://cdn.mysql.com//Downloads/MySQL-5.7/mysql-community-client-5.7.18-1.el6.x86_64.rpm
# wget https://cdn.mysql.com//Downloads/MySQL-5.7/mysql-community-libs-5.7.18-1.el6.x86_64.rpm
5. 检查查询发现，已经安装Mysql-5.1.73，版本非常低。必须重新安装，当前最新版本是5.7
# rpm -qa | grep mysql
mysql-server-5.1.73-5.el6_6.x86_64
mysql-libs-5.1.73-5.el6_6.x86_64
mysql-5.1.73-5.el6_6.x86_64
mysql-connector-odbc-5.1.5r1144-7.el6.x86_64
6. 准备安装，安装前，就怀疑，会不会覆盖？会不会冲突？安装一下试试，就知道了。
同时安装4个rpm包
# rpm -ivh mysql-community-server-5.7.18-1.el6.x86_64.rpm mysql-community-client-5.7.18-1.el6.x86_64.rpm mysql-community-common-5.7.18-1.el6.x86_64.rpm mysql-community-libs-5.7.18-1.el6.x86_64.rpm
7. 果然冲突了
warning: mysql-community-server-5.7.18-1.el6.x86_64.rpm: Header V3 DSA/SHA1 Signature, key ID 5072e1f5: NOKEY
Preparing... ########################################### [100%]
file /usr/share/mysql/czech/errmsg.sys from install of mysql-community-common-5.7.18-1.el6.x86_64 conflicts with file from package mysql-libs-5.1.73-5.el6_6.x86_64
file /usr/share/mysql/danish/errmsg.sys from install of mysql-community-common-5.7.18-1.el6.x86_64 conflicts with file from package mysql-libs-5.1.73-5.el6_6.x86_64
file /usr/share/mysql/dutch/errmsg.sys from install of mysql-community-common-5.7.18-1.el6.x86_64 conflicts with file from package mysql-libs-5.1.73-5.el6_6.x86_64
file /usr/share/mysql/english/errmsg.sys from install of mysql-community-common-5.7.18-1.el6.x86_64 conflicts with file from package mysql-libs-5.1.73-5.el6_6.x86_64
file /usr/share/mysql/estonian/errmsg.sys from install of mysql-community-common-5.7.18-1.el6.x86_64 conflicts with file from package mysql-libs-5.1.73-5.el6_6.x86_64
......
8. 经过查询，也安装失败了，还是5.1.73版本
# rpm -qa|grep mysql
mysql-server-5.1.73-5.el6_6.x86_64
mysql-libs-5.1.73-5.el6_6.x86_64
mysql-5.1.73-5.el6_6.x86_64
mysql-connector-odbc-5.1.5r1144-7.el6.x86_64
9. 开始卸载原有的5.1.73的Mysql，几种卸载方式，首推YUM方式卸载
# yum remove mysql
# rpm -e mysql // 普通删除模式
# rpm -e --nodeps mysql // 强力删除模式，如果使用上面命令删除时，提示有依赖的其它文件，则用该命令可以对其进行强力删除
10 .还剩余下面两个包
# rpm -qa|grep mysql
mysql-libs-5.1.73-5.el6_6.x86_64
mysql-connector-odbc-5.1.5r1144-7.el6.x86_64
11. 执行yum localinstall安装，发现需要卸载mysql-libs-5.1.73-5.el6_6.x86_64，通过yun卸载这个包后，可以安装了。
# yum localinstall mysql-community-server-5.7.18-1.el6.x86_64.rpm mysql-community-client-5.7.18-1.el6.x86_64.rpm mysql-community-common-5.7.18-1.el6.x86_64.rpm mysql-community-libs-5.7.18-
1.el6.x86_64.rpm
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Loaded plugins: fastestmirror, refresh-packagekit, security
Setting up Local Package Process
Examining mysql-community-server-5.7.18-1.el6.x86_64.rpm: mysql-community-server-5.7.18-1.el6.x86_64
Marking mysql-community-server-5.7.18-1.el6.x86_64.rpm to be installed
Loading mirror speeds from cached hostfile
* base: mirrors.163.com
* extras: mirrors.cn99.com
* updates: mirrors.163.com
Examining mysql-community-client-5.7.18-1.el6.x86_64.rpm: mysql-community-client-5.7.18-1.el6.x86_64
Marking mysql-community-client-5.7.18-1.el6.x86_64.rpm to be installed
Examining mysql-community-common-5.7.18-1.el6.x86_64.rpm: mysql-community-common-5.7.18-1.el6.x86_64
Marking mysql-community-common-5.7.18-1.el6.x86_64.rpm to be installed
Examining mysql-community-libs-5.7.18-1.el6.x86_64.rpm: mysql-community-libs-5.7.18-1.el6.x86_64
Marking mysql-community-libs-5.7.18-1.el6.x86_64.rpm to be installed
Resolving Dependencies
--> Running transaction check
---> Package mysql-community-client.x86_64 0:5.7.18-1.el6 will be installed
---> Package mysql-community-common.x86_64 0:5.7.18-1.el6 will be installed
---> Package mysql-community-libs.x86_64 0:5.7.18-1.el6 will be installed
---> Package mysql-community-server.x86_64 0:5.7.18-1.el6 will be installed
--> Finished Dependency Resolution
Dependencies Resolved
==================================================================================================================================
Package Arch Version Repository Size
==================================================================================================================================
Installing:
mysql-community-client x86_64 5.7.18-1.el6 /mysql-community-client-5.7.18-1.el6.x86_64 100 M
mysql-community-common x86_64 5.7.18-1.el6 /mysql-community-common-5.7.18-1.el6.x86_64 2.5 M
mysql-community-libs x86_64 5.7.18-1.el6 /mysql-community-libs-5.7.18-1.el6.x86_64 8.9 M
mysql-community-server x86_64 5.7.18-1.el6 /mysql-community-server-5.7.18-1.el6.x86_64 769 M
Transaction Summary
==================================================================================================================================
Install 4 Package(s)
Total size: 880 M
Installed size: 880 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-5.7.18-1.el6.x86_64 1/4
Installing : mysql-community-libs-5.7.18-1.el6.x86_64 2/4
Installing : mysql-community-client-5.7.18-1.el6.x86_64 3/4
Installing : mysql-community-server-5.7.18-1.el6.x86_64 4/4
Verifying : mysql-community-server-5.7.18-1.el6.x86_64 1/4
Verifying : mysql-community-libs-5.7.18-1.el6.x86_64 2/4
Verifying : mysql-community-common-5.7.18-1.el6.x86_64 3/4
Verifying : mysql-community-client-5.7.18-1.el6.x86_64 4/4
Installed:
mysql-community-client.x86_64 0:5.7.18-1.el6 mysql-community-common.x86_64 0:5.7.18-1.el6
mysql-community-libs.x86_64 0:5.7.18-1.el6 mysql-community-server.x86_64 0:5.7.18-1.el6
Complete!
12. 最后检查，已经安装成功
# rpm -qa|grep mysql
mysql-community-client-5.7.18-1.el6.x86_64
mysql-community-libs-5.7.18-1.el6.x86_64
mysql-community-common-5.7.18-1.el6.x86_64
mysql-community-server-5.7.18-1.el6.x86_64
13. 安装完成，但是启动的时候遇到了问题：
# service mysqld restart
Stopping mysqld: [ OK ]
Initializing MySQL database: 2017-07-11T15:23:50.462866Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2017-07-11T15:23:50.465315Z 0 [ERROR] --initialize specified but the data directory has files in it. Aborting.
2017-07-11T15:23:50.465365Z 0 [ERROR] Aborting
[FAILED]
14. 百度的解决方法（是由于之前老版本的数据库已经占用这个文件夹，需要清空，或者在/etc/my.cnf中重新指定--datadir）
保证 --datadir目录为空。 /usr/local/var/mysql 这个目录
15. 启动成功
# cd /var/lib/mysql
# ls
auto.cnf ib_buffer_pool ibdata1 ib_logfile0 ib_logfile1
# rm *
rm: remove regular file `auto.cnf'? y
rm: remove regular file `ib_buffer_pool'? y
rm: remove regular file `ibdata1'? y
rm: remove regular file `ib_logfile0'? y
rm: remove regular file `ib_logfile1'? y
# service mysqld restart
Stopping mysqld: [ OK ]
Initializing MySQL database: [ OK ]
Installing validate password plugin: [ OK ]
Starting mysqld: [ OK ]
# ps -ef|grep mysql
root 4533 1 0 23:25 pts/0 00:00:00 /bin/sh /usr/bin/mysqld_safe --datadir=/var/lib/mysql --socket=/var/lib/mysql/mysql.sock --pid-file=/var/run/mysqld/mysqld.pid --basedir=/usr --user=mysql
mysql 4727 4533 4 23:25 pts/0 00:00:00 /usr/sbin/mysqld --basedir=/usr --datadir=/var/lib/mysql --plugin-dir=/usr/lib64/mysql/plugin --user=mysql --log-error=/var/log/mysqld.log --pid-file=/var/run/mysqld/mysqld.pid --socket=/var/lib/mysql/mysql.sock
root 4762 3752 0 23:25 pts/0 00:00:00 grep mysql
16. 然而启动的过程中，又遇到一些问题，密码不知道了，重置密码
# mysql -u root
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)
[root@test mysql]# mysql -u root -p
Enter password:
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)
编辑mysql配置文件/etc/my.cnf，在[mysqld]这个条目下加入 skip-grant-tables 保存退出后重启mysql
# vi /etc/my.cnf
[root@test mysql]# service mysqld restart
Stopping mysqld: [ OK ]
Starting mysqld: [ OK ]
# mysql
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 4
Server version: 5.7.18 MySQL Community Server (GPL)
Copyright (c) 2000, 2017, 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 |
| sys |
+--------------------+
4 rows in set (0.00 sec)
设置密码，然后删除/etc/my.cnf中的 skip-grant-tables
再次重启mysql
mysql> use mysql;
Database changed
--.给root用户设置新密码：
5.7版本之前：
mysql> update user set password=password("新密码") where user="root";
Query OK, 1 rows affected (0.01 sec)
Rows matched: 1 Changed: 1 Warnings: 0
在5.7版本之后，mysql数据库下已经没有password这个字段了，password字段改成了authentication_string。
update mysql.user set authentication_string=PASSWORD('oracle') where User='root';mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)
---退出mysql，重启然后重新登录
# service mysqld restart
Stopping mysqld: [ OK ]
Starting mysqld: [ OK ]
# mysql -uroot -poracle
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 5
Server version: 5.7.18
Copyright (c) 2000, 2017, 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>
另外有需要云服务器可以了解下创新互联cdcxhl.cn，海内外云服务器15元起步，三天无理由+7*72小时售后在线，公司持有idc许可证，提供“云服务器、裸金属服务器、高防服务器、香港服务器、美国服务器、虚拟主机、免备案服务器”等云主机租用服务以及企业上云的综合解决方案，具有“安全稳定、简单易用、服务可用性高、性价比高”等特点与优势，专为企业上云打造定制，能够满足用户丰富、多元化的应用场景需求。
当前题目：Mysql卸载安装全过程-创新互联
标题来源：
http://cdkjz.cn/article/hseos.html
