Linux（centos）安装mysql8.0

一、下载mysql8.0安装包
1、在local创建mysql文件夹
cd /usr/local

mkdir mysql

cd mysql

2、使用wget下载mysql8.0的xz安装包
 wget https://dev.mysql.com/get/Downloads/MySQL-8.0/mysql-8.0.20-linux-glibc2.12-x86_64.tar.xz

二、解压mysql8.0安装包
1、解压
tar -xvf mysql-8.0.21-linux-glibc2.12-x86_64.tar.xz

2、重命名解压后的mysql文件夹（名字太长了）
mv mysql-8.0.21-linux-glibc2.12-x86_64 mysql8.0

3、创建data存储文件
cd mysql8.0

mkdir data

三、创建用户和用户组，并赋予权限
1、创建用户和用户组
groupadd mysql
 
useradd -g mysql mysql

2、给用户赋予权限
chown -R mysql.mysql /usr/local/mysql/mysql8.0

四、初始化mysql信息
1、切换到mysql8.0安装路径下
Tip：绝对路径：cd /usr/local/mysql/mysql8.0/bin

cd bin

2、初始化mysql基本信息
./mysqld --user=mysql --basedir=/usr/local/mysql/mysql8.0 --datadir=/usr/local/mysql/mysql8.0/data/ --initialize

3、获取到临时mysql密码

 五、添加mysqld服务到系统
1、将mysqld服务添加到系统中
cd /usr/local/mysql/mysql8.0

cp -a ./support-files/mysql.server /etc/init.d/mysql

2、授权以及添加服务
chmod +x /etc/init.d/mysql

chkconfig --add mysql

3、mysql5.7以后就没有my.cnf了，所以我们创建一个。（个人觉得方便一些）
cd /etc

sudo vim my.cnf

# Example MySQL config file for small systems.  
#  
# This is for a system with little memory (<= 64M) where MySQL is only used  
# from time to time and it's important that the mysqld daemon  
# doesn't use much resources.  
#  
# MySQL programs look for option files in a set of  
# locations which depend on the deployment platform.  
# You can copy this option file to one of those  
# locations. For information about these locations, see:  
# http://dev.mysql.com/doc/mysql/en/option-files.html  
#  
# In this file, you can use all long options that a program supports.  
# If you want to know which options a program supports, run the program  
# with the "--help" option.  
 
# The following options will be passed to all MySQL clients  
[client]  
default-character-set=utf8  
#password   = k0Ui&wV(Z3yt
port        = 3306 
socket      = /tmp/mysql.sock  
 
# Here follows entries for some specific programs  
 
# The MySQL server   
[mysqld]  
 
#配置mysql的文件夹 和 mysql data目录
basedir=/usr/local/mysql/mysql8.0
datadir=/usr/local/mysql/mysql8.0/data
default-storage-engine=INNODB  
character-set-server=utf8  
collation-server=utf8_general_ci  
port        = 3306 
socket      = /tmp/mysql.sock  
skip-external-locking  
key_buffer_size = 16K  
max_allowed_packet = 1M  
table_open_cache = 4 
sort_buffer_size = 64K  
read_buffer_size = 256K  
read_rnd_buffer_size = 256K  
net_buffer_length = 2K  
thread_stack = 128K  
 
# Don't listen on a TCP/IP port at all. This can be a security enhancement,  
# if all processes that need to connect to mysqld run on the same host.  
# All interaction with mysqld must be made via Unix sockets or named pipes.  
# Note that using this option without enabling named pipes on Windows  
# (using the "enable-named-pipe" option) will render mysqld useless!  
#   
#skip-networking  
server-id   = 1 
 
# Uncomment the following if you want to log updates  
#log-bin=mysql-bin  
 
# binary logging format - mixed recommended  
#binlog_format=mixed  
 
# Causes updates to non-transactional engines using statement format to be  
# written directly to binary log. Before using this option make sure that  
# there are no dependencies between transactional and non-transactional  
# tables such as in the statement INSERT INTO t_myisam SELECT * FROM  
# t_innodb; otherwise, slaves may diverge from the master.  
#binlog_direct_non_transactional_updates=TRUE  
 
# Uncomment the following if you are using InnoDB tables  
#innodb_data_home_dir = /usr/local/mysql/data  
#innodb_data_file_path = ibdata1:10M:autoextend  
#innodb_log_group_home_dir = /usr/local/mysql/data  
# You can set .._buffer_pool_size up to 50 - 80 %  
# of RAM but beware of setting memory usage too high  
#innodb_buffer_pool_size = 16M  
#innodb_additional_mem_pool_size = 2M  
# Set .._log_file_size to 25 % of buffer pool size  
#innodb_log_file_size = 5M  
#innodb_log_buffer_size = 8M  
#innodb_flush_log_at_trx_commit = 1 
#innodb_lock_wait_timeout = 50 
 
[mysqldump]  
quick  
max_allowed_packet = 16M  
 
[mysql]  
no-auto-rehash  
# Remove the next comment character if you are not familiar with SQL  
#safe-updates  
 
[myisamchk]  
key_buffer_size = 8M  
sort_buffer_size = 8M  
 
[mysqlhotcopy]  
interactive-timeout
*设置my.cnf权限

sudo chmod 664 /etc/my.cnf

 4、启动mysql服务（启动服务注意my.cnf文件中配置的3306端口是否被占用）
service mysql start

如果出现下面报错（1）

 解决
将/var/lock/subsys/下mysql文件删除

如果出现下面报错（2）

 先cat去查看这个err文件，端口占用解决方法

lsof -i tcp:3306

kill 26788

5、查看mysql服务状态
service mysql status

6、将mysql命令添加到服务  
ln -s /usr/local/mysql/mysql8.0/bin/mysql /usr/bin

六、登录mysql
1、登录 密码使用之前随机生成的密码
mysql  mysql -uroot -p

2、修改管理员密码  其中123456是新的密码自己设置 
ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY '123456';

3、重新加载缓存，使密码生效
flush privileges;

4、退出mysql，用新密码尝试登录管理员
七、修改mysql配置，使其可以用工具远程登录
mysql -uroot -p123456

use mysql

update user set host='%' where user='root';

// 赋予root全部权限

GRANT ALL PRIVILEGES ON *.* TO 'root'@'%'

 如果报错

 重新执行：

update user set host='%' where user='root';

再：

GRANT ALL PRIVILEGES ON *.* TO 'root'@'%';

为什么第二遍可以，应该是跟mysql缓存有关。

最后：

flush privileges;

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原文链接：https://blog.csdn.net/qq_45554167/article/details/121907007