CentOS 7.4下使用yum安装MySQL5.7.20

原文地址：CentOS 7.4下使用yum安装MySQL5.7.20

1.卸载  先停掉mysql进程   没有安装过的可以直接跳过

pkill -9 mysqld

        

 rpm -qa|grep -i mysql

        

      用命令 yum -y remove

      yum -y remove mysql-community-client-5.6.38-2.el7.x86_64

      卸载不掉的用 rpm -ev 

      依次卸载 直到没有

2.下载mysql的repo源 这个安装的mysql5.7.20  /**纠正一下，这源下载的是最新的版本  ****/

   [[e-mail] ~]# cd /usr/local/src/
   [[e-mail] src]# wget http://repo.mysql.com/mysql57-community-release-el7-8.noarch.rpm 

   [[e-mail] src]# rpm -ivh mysql57-community-release-el7-8.noarch.rpm 

   [[e-mail] src]#  yum -y install mysql-server 

（也可以指定安装目录     yum --installroot=/usr/local/mysql --releasever=/ -y install mysql-server  ）我没试，这样装环境变量配置都不用你管，装上直接启动就行。安装路径是默认的。

   

   一路 y 

 

根据步骤安装就可以了，

默认配置文件路径： 
配置文件：/etc/my.cnf 
日志文件：/var/log/var/log/mysqld.log 
服务启动脚本：/usr/lib/systemd/system/mysqld.service 
socket文件：/var/run/mysqld/mysqld.pid 

默认的配置文件/etc/my.cnf如下：

# 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

# 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
"/etc/my.cnf" 27L, 960C                                    27,1          Bot
# 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

# 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

不过安装完成后，密码为随机密码，需要重置密码。

3. 启动mysql服务

  service mysqld restart

 重置密码

    [[e-mail] ~]# grep "password" /var/log/mysqld.log    

    

    可以看到  输入 mysql -u root -p   密码 进入      第一次登陆 ，需要重置密码 要不什么也不能操作 

        

       接下来重置密码：5.7.20 为了安全，密码必须包含 数字字母符号

       alter user 'root'@'localhost' identified by 'Root!!2018';  

    最后记得刷新权限；

    flush privileges 

    也可以 直接再添加新用户     

    CREATE USER ‘root’@‘%‘ IDENTIFIED BY ‘您的密码‘;

    grant all on *.* to 'root001'@'%' identified by '[e-mail]@'  with grant option;

    增加root用户指定可以任意IP登录，如果想限制只能让指定IP登录请把%替换成IP地址