Centos7.6安装MySQL5.7.25（所有步骤可直接复制粘贴）

1. 下载

wget https://cdn.mysql.com//Downloads/MySQL-5.7/mysql-5.7.25-linux-glibc2.12-x86_64.tar.gz

2. 检测是否有旧版本或者以前的安装残留

rpm -qa | grep mysql

• 如有，类似

mysql-libs-5.1.52-1.el6_0.1.x86_64

• 卸载

rpm -e --nodeps mysql-libs-5.1.52-1.el6_0.1.x86_64

3. 检查是否存在 mariadb 数据库

rpm -qa | grep mariadb

• 如有，类似

rpm -qa | grep mariadb

• 卸载

rpm -e --nodeps mariadb-libs-5.5.56-2.el7.x86_64

4. 解压安装

tar zvf mysql-5.7.25-linux-glibc2.12-x86_64.tar.gz -C /opt
mv /opt/mysql-5.7.25-linux-glibc2.12-x86_64 /opt/mysql-5.7.25

5. 配置MySQL环境变量

tee -a /etc/profile <<-'EOF'
# wlf-2020-09-21
export PATH=$PATH:/opt/mysql-5.7.25/bin
EOF

source /etc/profile

6. 检查系统是否有mysql组和mysql用户

cat /etc/group | grep mysql
#类似
mysql:x:490:

cat /etc/passwd | grep mysql
#类似
mysql:x:496:490::/home/mysql:/bin/bash

• 以上为存在的情况，如无，执行添加命令：

groupadd mysql
useradd -r -g mysql mysql
#useradd -r参数表示mysql用户是系统用户，不可用于登录系统

7. 创建data目录

mkdir /opt/mysql-5.7.25/data

8. 修改MySQL目录属主属组

chown -R mysql.mysql /opt/mysql-5.7.25

9. 创建默认配置文件

cd /opt/mysql-5.7.25/support-files
vim my_default.cnf

• 添加如下内容

# For advice on how to change settings please see
# http://dev.mysql.com/doc/refman/5.7/en/server-configuration-defaults.html
# *** DO NOT EDIT THIS FILE. It's a template which will be copied to the
# *** default location during install, and will be replaced if you
# *** upgrade to a newer version of MySQL.
 
 
[mysqld]
sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES 
 
basedir = /opt/mysql-5.7.25
datadir = /opt/mysql-5.7.25/data
port = 3306
socket = /tmp/mysql.sock
character-set-server=utf8
 
log-error = /opt/mysql-5.7.25/data/mysqld.log
pid-file = /opt/mysql-5.7.25/data/mysqld.pid

10. 拷贝MySQL配置文件

\cp /opt/mysql-5.7.25/support-files/my_default.cnf /etc/my.cnf

11. 初始化 mysqld

mysqld --initialize --user=mysql --basedir=/opt/mysql-5.7.25/ --datadir=/opt/mysql-5.7.25/data/

12. 获取临时密码

[root@cloudansys ~]# grep password /opt/mysql-5.7.25/data/mysqld.log
2020-09-21T02:04:18.317577Z 1 [Note] A temporary password is generated for root@localhost: e#oE#EG,g6Ai

• 如上，我的密码为【e#oE#EG,g6Ai】

13. 配置MySQL开机启动

cp /opt/mysql-5.7.25/support-files/mysql.server /etc/init.d/mysql

14. 启动MySQL

service mysql start

15. 登录mysql，密码为初始临时密码

mysql -u root -pe#oE#EG,g6Ai

16.修改密码

mysql> set password=password('123456');
mysql> grant all privileges on *.* to root@'%' identified by '123456';
mysql> flush privileges;

17. 添加远程访问权限

mysql> use mysql;
mysql> update user set host='%' where user = 'root';
mysql> flush privileges;

• 最终如下所示，即最终目的是把用户root的host设置为%

mysql> use mysql;
mysql> select user,host,authentication_string from user;
+------+------+-------------------------------------------+
| user | host | authentication_string                     |
+------+------+-------------------------------------------+
| root | %    | *81F5E21E35407D884A6CD4A731AEBFB6AF209E1B |
+------+------+-------------------------------------------+
1 row in set (0.00 sec)

mysql>

• 其他用户都可以删除掉

mysql> use mysql;
mysql> delete from user where root<>'root' and host<>'%';
Query OK, 3 rows affected (0.00 sec)

mysql>

18. 重启mysql生效

service mysql restart