centos7之Mysql安装

环境准备

　　从CentOS 7.0发布以来，yum源中开始使用mariadb来代替MySQL的安装。即使你输入的是yum install mysql , 显示的也是mariadb的安装内容。

　　首先先卸载mariadb。

　　检查mariadb是否已安装

[root@localhost ~]# yum list installed | grep mariadb  
mariadb-libs.x86_64                  1:5.5.56-2.el7                    @anaconda

　　全部卸载

[root@localhost ~]#  yum -y remove mariadb*  
Loaded plugins: fastestmirror
Resolving Dependencies
--> Running transaction check
---> Package mariadb-libs.x86_64 1:5.5.56-2.el7 will be erased
--> Processing Dependency: libmysqlclient.so.18()(64bit) for package: 2:postfix-2.10.1-6.el7.x86_64
--> Processing Dependency: libmysqlclient.so.18(libmysqlclient_18)(64bit) for package: 2:postfix-2.10.1-6.el7.x86_64
--> Running transaction check
---> Package postfix.x86_64 2:2.10.1-6.el7 will be erased
--> Finished Dependency Resolution

Dependencies Resolved

=======================================================================================================================================================================
 Package                                  Arch                               Version                                       Repository                             Size
=======================================================================================================================================================================
Removing:
 mariadb-libs                             x86_64                             1:5.5.56-2.el7                                @anaconda                             4.4 M
Removing for dependencies:
 postfix                                  x86_64                             2:2.10.1-6.el7                                @anaconda                              12 M

Transaction Summary
=======================================================================================================================================================================
Remove  1 Package (+1 Dependent package)

Installed size: 17 M
Downloading packages:
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
  Erasing    : 2:postfix-2.10.1-6.el7.x86_64                                                                                                                       1/2 
  Erasing    : 1:mariadb-libs-5.5.56-2.el7.x86_64                                                                                                                  2/2 
  Verifying  : 1:mariadb-libs-5.5.56-2.el7.x86_64                                                                                                                  1/2 
  Verifying  : 2:postfix-2.10.1-6.el7.x86_64                                                                                                                       2/2 

Removed:
  mariadb-libs.x86_64 1:5.5.56-2.el7                                                                                                                                   

Dependency Removed:
  postfix.x86_64 2:2.10.1-6.el7                                                                                                                                        

Complete!

 

安装Mysql

　　一、下载安装官方提供的yum rpm包

　　下载网页：https://dev.mysql.com/downloads/repo/yum/

　　点击Red Hat Enterprise Linux 7 / Oracle Linux 7 (Architecture Independent), RPM Package后面的download，进入新的页面点击No thanks, just start my download.就可以看到下载源地址了。

　　下载wget https://repo.mysql.com//mysql80-community-release-el7-1.noarch.rpm

wget https://repo.mysql.com//mysql80-community-release-el7-1.noarch.rpm

　　安装rpm包

rpm -ivh mysql80-community-release-el7-1.noarch.rpm

　　检查mysql的yum源是否安装成功：yum repolist enabled | grep "mysql.*-community.*" 

[root@localhost src]# yum repolist enabled | grep "mysql.*-community.*"
mysql-connectors-community/x86_64       MySQL Connectors Community           51
mysql-tools-community/x86_64            MySQL Tools Community                63
mysql80-community/x86_64                MySQL 8.0 Community Server           17

　　二、使用yum install mysql-server安装（这里会有点慢）

yum -y  install mysql-server

[root@localhost ~]# rpm -qi mysql-community-server  
Name        : mysql-community-server
Version     : 8.0.11
Release     : 1.el7
Architecture: x86_64
Install Date: Thu 17 May 2018 09:40:08 PM EDT
Group       : Applications/Databases
Size        : 1633523890
License     : Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved. Under GPLv2 license as shown in the Description field.
Signature   : DSA/SHA1, Sun 08 Apr 2018 01:07:21 PM EDT, Key ID 8c718d3b5072e1f5
Source RPM  : mysql-community-8.0.11-1.el7.src.rpm
Build Date  : Sun 08 Apr 2018 03:29:08 AM EDT
Build Host  : siv27.no.oracle.com
Relocations : (not relocatable)
Packager    : MySQL Release Engineering <[e-mail]>
Vendor      : Oracle and/or its affiliates
URL         : http://www.mysql.com/
Summary     : A very fast and reliable SQL database server
Description :
The MySQL(TM) software delivers a very fast, multi-threaded, multi-user,
and robust SQL (Structured Query Language) database server. MySQL Server
is intended for mission-critical, heavy-load production systems as well
as for embedding into mass-deployed software. MySQL is a trademark of
Oracle and/or its affiliates

The MySQL software has Dual Licensing, which means you can use the MySQL
software free of charge under the GNU General Public License
(http://www.gnu.org/licenses/). You can also purchase commercial MySQL
licenses from Oracle and/or its affiliates if you do not wish to be bound by the terms of
the GPL. See the chapter "Licensing and Support" in the manual for
further info.

The MySQL web site (http://www.mysql.com/) provides the latest news and
information about the MySQL software.  Also please see the documentation
and the manual for more information.

This package includes the MySQL server binary as well as related utilities
to run and administer a MySQL server.

 

　　三、启动mysql

[root@localhost ~]# service mysqld start  
Redirecting to /bin/systemctl start mysqld.service

　　四、使用初始密码登录

[root@localhost ~]# cat /var/log/mysqld.log|grep 'A temporary password' 
2018-05-18T02:01:17.558742Z 5 [Note] [MY-010454] [Server] A temporary password is generated for root@localhost: belPU>iuF4*H

　　最后一行冒号后面的部分belPU>iuF4*H就是初始密码。 

　　五、mysql5.7开始对root密码复杂性要求很高，必须有数字、字母大小写、符号（应该是需要8位以上），这里我么还查show databases；不了。

[root@localhost ~]# mysql -uroot -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 10
Server version: 8.0.11

Copyright (c) 2000, 2018, 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;
ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.

　　只需要把root密码更改的复杂一些即可。

　　更改密码方法：

解决办法
1、 修改用户密码
mysql> alter user 'root'@'localhost' identified by 'youpassword';  

或者（下面这个只能修改当前登录的用户密码）       

mysql> set password=password("youpassword");
2、刷新权限
mysql> flush privileges;

　　示例

mysql> alter user 'root'@'localhost' identified by 'qA123,./';
Query OK, 0 rows affected (0.10 sec)

mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)

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

　　重启mysqld服务。

[root@localhost ~]# systemctl restart mysqld.service

　　

常用的命令：

systemctl start mysqld    #启动mysqld
systemctl stop mysqld    #停止mysqld
systemctl restart mysqld    #重启mysqld
systemctl enable mysqld   #设置开机启动

systemctl status mysqld    #查看 MySQL Server 状态