在centos7下采用绿色版安装mysql8.0.13版本
1.下载安装包
到https://dev.mysql.com/downloads/mysql/下选择社区版(Community),然后下滑，选择通用linux版，下载64位的压缩包。
我下载的是第一个链接。安装时先要进行xz解压缩。由于本人电脑为win10系统，centos就装到了VM里，上传centos7里(rz，ftp均可)的tmp目录(省的忘记)。
解压缩mysql-8.0.13-linux-glibc2.12-x86_64.tar.xz，
xz -d mysql-8.0.13-linux-glibc2.12-x86_64.tar.xz
tar -xvf mysql-8.0.13-linux-glibc2.12-x86_64.tar。
等tar完成， 将解压后的文件夹拷贝到/usr/local/并重命名为mysql
mv -f mysql-8.0.13-linux-glibc2.12-x86_64 /usr/local/mysql
查看系统是否有libaio包，如果没有无法运行mysql数据库
rpm -qa | grep libaio
libaio-0.3.107-10.el6.x86_64 //表示已经安装
2.建立mysql用户和用户组：
useradd -s /sbin/nologin -M mysql
修改/usr/local/mysql文件夹的属主和属组为mysql
chown -R mysql:mysql mysql
3.初始化数据库
启动/usr/local/mysql/bin/目录下的mysqld
./mysqld --initialize --user=mysql
注意其中一句，这是mysql数据库自动生成的临时root密码，一定要记录下来********A temporary password is generated for root@localhost: +&)iV1&tA-pw
4.配置数据库
创建 /usr/local/mysql/support-files/my-default.cnf
因为本次实验简单，无多余的复杂配置,且大多是默认的配置，仅添加一些基础的必要配置，如下:
[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
# These are commonly set, remove the # and set as required.
basedir = /usr/local/mysql
#mysql数据库文件夹所在位置
datadir = /var/lib/mysql
#mysql数据库的数据文件所在位置
# port = .....
# server_id = .....
socket = /var/lib/mysql/mysql.sock
#mysql sock位置
# 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
character-set-server=utf8
#修改mysql服务器默认的字符集
#此句不是必须
sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES
[client]
socket = /var/lib/mysql/mysql.sock
default-character-set=utf8
保存退出，然后复制到/etc/my.cnf
cp /usr/local/mysql/support-files/my-default.cnf /etc/my.cnf
5.启动并测试数据库
启动数据库
cp /usr/local/mysql/support-files/mysql.server /etc/init.d/mysqld
service mysqld start
连接测试数据库
cd /usr/local/mysql/bin
./mysql -u root -p
输入保存的临时密码，进入mysql后先修改root的密码，否则大部分操作都无法进行。修改密码格式如下:
ALTER USER 'username'@'连接的数据库' IDENTIFIED BY 'newpas'.
eg:ALTER USER 'root'@'localhost' IDENTIFIED BY '123456';
完成！！
附录:
非必要配置
修改环境变量和ld.so.conf
将含有mysql命令的目录添加到环境变量
vim /etc/profile
PATH=/usr/local/mysql/bin:$PATH
export PATH
将mysql目录下的lib目录添加到ld.so.conf文件
vim /etc/ld.so.conf
include /usr/local/mysql/lib/
保存退出后输入
ldconfig
