前言
首次在Linux系统上使用MySql，笔记还是要记录一下的。
进入正题
本次笔者使用YUM安装MySql
1、进入存放安装包位置文件夹
cd /usr/src/
2、查看系统中是否已安装MySql服务，有两种方式
rpm -qa | grep mysql
yum list installed | grep mysql
3、如果已存在，则删除MySql及其依赖项
yum -y remove mysql-libs.x86_64
4、下载 mysql57-community-release-el7-8.noarch.rpm 的 YUM 源
wget http://repo.mysql.com/mysql57-community-release-el7-8.noarch.rpm
5、安装 mysql57-community-release-el7-8.noarch.rpm
rpm -ivh mysql57-community-release-el7-8.noarch.rpm
6、安装 MySql,一路 Y 到底
yum install mysql-server
安装完毕后，运行mysql，然后在 /var/log/mysqld.log 文件中会自动生成一个随机的密码，我们需要先取得这个随机密码，以用于登录 MySQL 服务端
service mysqld start
grep "password" /var/log/mysqld.log
将会返回如下内容，末尾字符串就是密码，把它保存下来
A temporary password is generated for root@localhost: 2ru>oFqj+fHw
7、登录到 MySQL 服务端并更新用户 root 的密码
mysql -u root -p
2ru>oFqj+fHw
登陆后更改密码(密码使用了强度验证，所以需要有一定强度的密码)
ALTER USER 'root'@'localhost' identified by 'Root123456..(新密码)';
flush privileges;
设置用户 root 可以在任意 IP 下被访问
grant all privileges on *.* to root@"%" identified by 'Root123456..';
设置用户 root 可以在本地被访问
grant all privileges on *.* to root@"localhost" identified by 'Root123456..';
然后刷新权限后生效
flush privileges;
这样环境就搭建完成了。
注意：如果用远程工具还是连接不上，试试用 iptables -F 命令来清除防火墙中链中的规则
8.修改配置表
打开配置表，文件路径：
/etc/my.cnf
设置 MySQL 的字符集为 UTF-8
# For advice on how to change settings please see
# http://dev.mysql.com/doc/refman/5.7/en/server-configuration-defaults.html
# 设置 MySQL 的字符集为 UTF-8
[client]
default-character-set=utf8
[mysqld]
# 设置 MySQL 的字符集为 UTF-8
character_set_server=utf8
#
# Remove leading # and set to the amount of RAM for the most important data
# cache in MySQL. Start at 70% of total RAM for dedicated server, else 10%.
# innodb_buffer_pool_size = 128M
#
# Remove leading # to turn on a very important data integrity option: logging
# changes to the binary log between backups.
# log_bin
#
# Remove leading # to set options mainly useful for reporting servers.
# The server defaults are faster for transactions and fast SELECTs.
# Adjust sizes as needed, experiment to find the optimal values.
# join_buffer_size = 128M
# sort_buffer_size = 2M
# read_rnd_buffer_size = 2M
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid
重启MySql后登陆，查看字符集
show variables like '%character%';
9.MySQL 采用的 TCP/IP 协议传输数据，默认端口号为 3306，我们可以通过如下命令查看
netstat -anp
常用Sql命令
--执行 sql 脚本
\. <sql文件绝对路径>
--查看MySql数据库物理文件存放位置
mysql> show global variables like "%datadir%";
常用的相关管理Shell命令
service mysqld start; 启动
service mysqld stop; 停止
service mysqld restart; 重启
service mysqld status; 查看状态
systemctl start mysqld
service mysqld stop
service mysqld restart
systemctl status mysqld
