一、系统环境
[root@localhost ~]# cat /etc/redhat-release
CentOS Linux release 7.6.1810 (Core)
二、mysql安装
#yum install mysql mysql-server mysql-devel
安装mysql-server失败，如下图：
[root@localhost ~]# yum install mysql-server
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
- base: mirrors.sina.cn
- extras: mirrors.sina.cn
- updates: mirrors.sina.cn
No package mysql-server available.
Error: Nothing to do
这是因为CentOS 7用mariadb代替了MySQL数据库软件。
有两种解决办法：
1、方法一：安装mariadb
MariaDB数据库管理系统是MySQL的一个分支，主要由开源社区在维护，采用GPL授权许可。开发这个分支的原因之一是：甲骨文公司收购了MySQL后，有将MySQL闭源的潜在风险，因此社区采用分支的方式来避开这个风险。MariaDB的目的是完全兼容MySQL，包括API和命令行，使之能轻松成为MySQL的代替品。
安装mariadb，大小59 M。
[root@localhost ~]# yum install mariadb-server mariadb
mariadb数据库的相关命令是：
systemctl start mariadb #启动MariaDB
systemctl stop mariadb #停止MariaDB
systemctl restart mariadb #重启MariaDB
systemctl enable mariadb #设置开机启动
所以先启动数据库
[root@localhost ~]# systemctl start mariadb
然后就可以正常使用mysql了
[root@localhost ~]# mysql -u root -p
Enter password:
Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MariaDB connection id is 3
Server version: 5.5.41-MariaDB MariaDB Server
Copyright (c) 2000, 2014, Oracle, MariaDB Corporation Ab and others.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
MariaDB [(none)]> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| test |
+--------------------+
4 rows in set (0.00 sec)
MariaDB [(none)]>
安装mariadb后显示的也是 MariaDB [(none)]> ，可能看起来有点不习惯。下面是第二种方法。
2、方法二：官网下载安装mysql-server
下载mysql：
wget http://dev.mysql.com/get/mysql-community-release-el7-5.noarch.rpm
源码安装：
rpm -ivh mysql-community-release-el7-5.noarch.rpm
安装服务：
yum install mysql-community-server
安装成功后重启mysql服务。
service mysqld restart
初次安装mysql，root账户没有密码。
[root@localhost ~]# mysql -u root
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 3
Server version: 5.6.26 MySQL Community Server (GPL)
Copyright (c) 2000, 2015, 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 (0.01 sec)
mysql>
设置mysql登录密码：
mysql> set password for 'root'@'localhost' =password('password');
Query OK, 0 rows affected (0.00 sec)
mysql>
不需要重启数据库即可生效。
在mysql安装过程中如下内容：
Installed:
mysql-community-client.x86_64 0:5.6.26-2.el7 mysql-community-devel.x86_64 0:5.6.26-2.el7
mysql-community-libs.x86_64 0:5.6.26-2.el7 mysql-community-server.x86_64 0:5.6.26-2.el7
Dependency Installed:
mysql-community-common.x86_64 0:5.6.26-2.el7
Replaced:
mariadb.x86_64 1:5.5.41-2.el7_0 mariadb-devel.x86_64 1:5.5.41-2.el7_0 mariadb-libs.x86_64 1:5.5.41-2.el7_0
mariadb-server.x86_64 1:5.5.41-2.el7_0
所以安装完以后mariadb自动就被替换了，将不再生效。
[root@localhost ~]# rpm -qa |grep mariadb
[root@localhost ~]#
三、配置mysql
1、编码
mysql配置文件为/etc/my.cnf
最后加上编码配置
[mysql]
default-character-set =utf8
这里的字符编码必须和/usr/share/mysql/charsets/Index.xml中一致。
2、远程连接设置
把在所有数据库的所有表的所有权限赋值给位于所有IP地址的root用户。
mysql> grant all privileges on . to root@'%'identified by 'password';
如果是新用户而不是root，则要先新建用户
mysql>create user 'username'@'%' identified by 'password';
此时就可以进行远程连接了。