MySQL安装改密

前置条件

centos删除原有mysql

删除旧的所有mysql （一定要将mariaDB包和自带mysql包卸载干净，否则安装时出现各种奇妙错误，导致失败。）

rpm -qa | grep -i mariadb
rpm -e --nodeps mariadb-libs-5.5.56-2.el7.x86_64
rpm -qa | grep -i mysql
rpm -e MySQL-client-5.6.38-1.el7.x86_64

删除服务

chkconfig --list | grep -i mysql //查看服务
chkconfig --del mysql //删除服务

删除mysql分散的文件夹

whereis mysql
rm -rf /use/lib/mysql
rm -rf /etc/my.cnf #删除系统默认的配置文件

ubuntu 删除原有mysql

dpkg -l | grep mysql
#ii  mysql-client-core-8.0                  8.0.37-0ubuntu0.22.04.3                 amd64        MySQL database core client binaries
apt-get remove mysql-client-core-8.0

查看开机自启服务

systemctl list-unit-files --type=service | grep enabled

删除mysql分散的文件夹

whereis mysql
rm -rf /use/lib/mysql
rm -rf /etc/my.cnf #删除系统默认的配置文件

centos yum安装

配置yum源

wget https://dev.mysql.com/get/mysql57-community-release-el7-9.noarch.rpm

rpm -ivh mysql57-community-release-el7-9.noarch.rpm

执行完成后会在/etc/yum.repos.d/目录下生成两个repo文件mysql-community.repo mysql-community-source.repo

yum install mysql-server -y --nogpgcheck 

启动mysql

systemctl start mysqld

官网下载打包文件，解压就可用

官网地址：

https://downloads.mysql.com/archives/community/

上传服务器后解压：

tar -zxvf mysql-5.7.24-linux-glibc2.12-x86_64.tar.gz
mv -v mysql-5.7.24-linux-glibc2.12-x86_64 /usr/local/mysql

创建用户和组

groupadd mysql
useradd -r -g mysql mysql

将安装目录所有者及所属组改为mysql ，这个根据自己的目录来

chown -R mysql.mysql /usr/local/mysql

在mysql目录下创建data文件夹

cd /usr/local/mysql
mkdir data 

centos 需要安装相关依赖

yum -y install numactl
yum install libaio

初始化数据库,会自动生成密码

/usr/local/mysql/bin/mysqld --user=mysql --basedir=/usr/local/mysql/ --datadir=/usr/local/mysql/data --initialize

ubuntu 需要安装相关依赖

apt-get install numactl
apt-get install libncurses5

初始化数据库

/usr/local/mysql/scripts/mysql_install_db --user=mysql --basedir=/usr/local/mysql --datadir=/usr/local/mysql/data

配置my.cnf

vim /etc/my.cnf

[mysqld]
datadir=/usr/local/mysql/data
basedir=/usr/local/mysql
socket=/tmp/mysql.sock
user=mysql
port=3306
character-set-server=utf8
#取消密码验证
#skip-grant-tables
#Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
[mysqld_safe]
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid

将mysql加入到启动服务，设为开机启动，然后启动mysql

cp /usr/local/mysql/support-files/mysql.server /etc/init.d/mysql
chkconfig mysql on
service mysql start

配置环境变量

没有设置环境变量的情况下：

/usr/local/mysql/bin/mysql -uroot -p

也可以先设置一下环境变量：

echo "PATH=$PATH:/usr/local/mysql/bin">> ~/.bashrc

进入数据库后更改密码

set password=password('redhat');

初始化常见报错信息

Fatal error: Can't open and lock privilege tables: Table 'mysql.host' doesn't exist

mysql_install_db --user=mysql

如没有mysql_install_db命令。

find / -name  mysql_install_db 查找mysql_install_db

#例如在/usr/local/mysql/scripts/mysql_install_db
cd /usr/local/mysql 
#执行
./scripts/mysql_install_db --user=mysql

mysql8.0安装方法：

wget https://downloads.mysql.com/archives/get/p/23/file/mysql-8.0.30-1.el7.x86_64.rpm-bundle.tar
tar -xvf mysql-8.0.30-1.el7.x86_64.rpm-bundle.tar  #把文件释放出来
yum install -y  mysql-community*   #安装mysql
systemctl start mysqld #启动数据库
systemctl enable mysqld #加入开机自启
firewall-cmd --permanernt --add-service=mysql  #加入防火墙
firewall-cmd --reload 
cat /var/log/mysqld.log | grep localhost  #查看默认密码
mysql -uroot -p  #进入数据库

修改密码8.0版本

更改密码为空即‘mima’处无内容，即为免密（亦可设置你习惯的密码，就不是免密了）

alter user 'root'@'localhost' identified by 'mima';
flush privileges;
exit