Centos7安装mysql

安装MySql

1、先需要查看系统当中有没有安装mariadb

mariadb和mysql同源

ps ajx |grep mariadb

2、把mariadb.service停掉

systemctl stop mariadb.service

3、检测是否被停掉

ps axj |grep mariadb

4、查看mariadb/mysql安装的rpm包

 rpm -qa |grep mariadb

rpm -qa |grep mysql

5、卸载显示出来的mariadb/mysql安装包

sudo yum remove mariadb

备份/etc/my.cnf,备份/var/lib/mysql数据

6、安装
获取mysql官方yum源 ：http://repo.mysql.com/

wget http://repo.mysql.com/mysql57-community-release-el7-10.noarch.rpm

对比前后yum源

ls /etc/yum.repos.d/ -al

安装yum源

sudo rpm -Uvh mysql57-community-release-el7-10.noarch.rpm

对比前后yum源

ls /etc/yum.repos.d/ -al

查看能不能正常工作

yum list |grep mysql

安装mysql服务

sudo yum install -y mysql-community-server

如果显示安装失败需要加上 --nogpgcheck

sudo yum install -y mysql-community-server --nogpgcheck

查看配置文件

ls /etc/my.cnf

sudols /var/lib/mysql

启动服务

systemctl start mysqld.service

（停止服务：systemctl stop mysqld）
查看启动服务

ps axj |grep mysqld

sudols -al /var/lib/mysql

7、密码
获取临时root密码

sudogrep'temporary password' /var/log/mysqld.log

使用临时root 密码

mysql -uroot -p

判断修改密码时候新密码是否符合当前的策略，不满足报错，不让修改，Mysql的密码级别有三种，0级别，1级别，2级别 0级别允许是纯数字，1级别必须包含数字和字母，2级别必须数字，大小写字母都包含。
次操作密码设置为最低级别：

set global validate_password_policy=0;

设置密码最小长度

set global validate_password_length=1;

修改本地密码，暂不授权远端登录

ALTER USER 'root'@'localhost' IDENTIFIED BY '123456';

FLUSH PRIVILEGES;

开启开机自启动

systemctl enable mysqld
systemctl daemon-reload

8、配置 /etc/my.cnf
主要是数据库客户端和服务器的编码格式

# For advice on how to change settings please see# http://dev.mysql.com/doc/refman/5.7/en/server-configuration-defaults.html[mysqld]## 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
port=3306
# 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
character-set-server=utf8

default-storage-engine=innodb

9、确保终端命令行中可以输入中文
mysql 已经配置了客户端服务器utf8编码，但是无法输入中文

env|grep LANG