安装前准备

一安装前准备

1、检查是否已经安装过mysql，执行命令

[root@localhost /]# rpm -qa | grep mysql

从执行结果，可以看出我们已经安装了mysql-libs-5.1.73-5.el6_6.x86_64，执行删除命令

[root@localhost /]# rpm -e --nodeps mysql-libs-5.1.73-5.el6_6.x86_64

再次执行查询命令，查看是否删除

[root@localhost /]# rpm -qa | grep mysql

2、查询所有Mysql对应的文件夹

[root@localhost /]# whereis mysql
mysql: /usr/bin/mysql /usr/include/mysql
[root@localhost lib]# find / -name mysql
/data/mysql
/data/mysql/mysql

删除相关目录或文件

[root@localhost /]#  rm -rf /usr/bin/mysql /usr/include/mysql /data/mysql /data/mysql/mysql

验证是否删除完毕

[root@localhost /]# whereis mysql
mysql:
[root@localhost /]# find / -name mysql
[root@localhost /]#

3、检查mysql用户组和用户是否存在，如果没有，则创建

[root@localhost /]# cat /etc/group | grep mysql
[root@localhost /]# cat /etc/passwd |grep mysql
[root@localhost /]# groupadd mysql
[root@localhost /]# useradd -r -g mysql mysql
[root@localhost /]#

4、从官网下载是用于Linux的Mysql安装包

下载命令：

[root@localhost /]#  wget https://dev.mysql.com/get/Downloads/MySQL-5.7/mysql-5.7.24-linux-glibc2.12-x86_64.tar.gz

也可以直接到 mysql官网选择对应版本进行下载。

下载安装包
wget https://dev.mysql.com/get/Downloads/MySQL-8.0/mysql-8.0.12-linux-glibc2.12-x86_64.tar.xz

Linux下安装mysql8.0.20 - 图2

解压

xz -d mysql-8.0.12-linux-glibc2.12-x86_64.tar.xz
tar -xvf mysql-8.0.12-linux-glibc2.12-x86_64.tar

二安装Mysql

1、在执行wget命令的目录下或你的上传目录下找到Mysql安装包：mysql-5.7.24-linux-glibc2.12-x86_64.tar.gz

执行解压命令：

[root@localhost /]#  tar xzvf mysql-5.7.24-linux-glibc2.12-x86_64.tar.gz

解压完成后，可以看到当前目录下多了一个解压文件，移动该文件到/usr/local/下，并将文件夹名称修改为mysql。

如果/usr/local/下已经存在mysql，请将已存在mysql文件修改为其他名称，否则后续步骤可能无法正确进行。

执行命令如下：

[root@localhost /]# mv mysql-5.7.24-linux-glibc2.12-x86_64 /usr/local/
[root@localhost /]# cd /usr/local/
[root@localhost /]# mv mysql-5.7.24-linux-glibc2.12-x86_64 mysql

如果/usr/local/下不存在mysql文件夹，直接执行如下命令，也可达到上述效果。

[root@localhost /]# mv mysql-5.7.24-linux-glibc2.12-x86_64 /usr/local/mysql

2、在/usr/local/mysql目录下创建data目录

[root@localhost /]# mkdir /usr/local/mysql/data

3、更改mysql目录下所有的目录及文件夹所属的用户组和用户，以及权限

[root@localhost /]# chown -R mysql:mysql /usr/local/mysql
[root@localhost /]# chmod -R 755 /usr/local/mysql

4、编译安装并初始化mysql,务必记住初始化输出日志末尾的密码（数据库管理员临时密码）

[root@localhost /]# cd /usr/local/mysql/bin
[root@localhost bin]# ./mysqld --initialize --user=mysql --datadir=/usr/local/mysql/data --basedir=/usr/local/mysql

补充说明：
第4步时，可能会出现错误：出现该问题首先检查该链接库文件有没有安装使用命令进行核查

[root@localhost bin]# rpm -qa|grep libaio   
[root@localhost bin]#

运行命令后发现系统中无该链接库文件

[root@localhost bin]#  yum install  libaio-devel.x86_64

安装成功后，继续运行数据库的初始化命令，此时可能会出现如下错误：执行如下命令后：

[root@localhost bin]#  yum -y install numactl

执行无误之后，再重新执行第4步初始化命令，无误之后再进行第5步操作！

5、运行初始化命令成功后，输出日志如下：

记录日志最末尾位置root@localhost:后的字符串，此字符串为mysql管理员临时登录密码。

6、编辑配置文件my.cnf，添加配置如下

[root@localhost bin]#  vi /etc/my.cnf
[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
datadir = /usr/local/mysql/data
socket = /tmp/mysql.sock
log-error = /usr/local/mysql/data/error.log
pid-file = /usr/local/mysql/data/mysql.pid
port = 3306
#lower_case_table_names = 1
# server_id = .....
# socket = .....
#lower_case_table_names = 1
max_allowed_packet=32M
default-authentication-plugin = mysql_native_password
#lower_case_file_system = on
#lower_case_table_names = 1
log_bin_trust_function_creators = ON
# 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 
sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES

lower_case_table_names：是否区分大小写，1表示存储时表名为小写，操作时不区分大小写；0表示区分大小写；不能动态设置，修改后，必须重启才能生效：
character_set_server：设置数据库默认字符集，如果不设置默认为latin1
innodb_file_per_table：是否将每个表的数据单独存储，1表示单独存储；0表示关闭独立表空间，可以通过查看数据目录，查看文件结构的区别；

7、测试启动mysql服务器

[root@localhost /]# /usr/local/mysql/support-files/mysql.server start

显示如下结果，说明数据库安装并可以正常启动

8、

[root@localhost /]#  ln -s /usr/local/mysql/support-files/mysql.server /etc/init.d/mysql 
[root@localhost /]#  ln -s /usr/local/mysql/bin/mysql /usr/bin/mysql
[root@localhost /]#  ln -s /usr/local/mysql/bin/mysqldump /usr/bin/mysqldump
[root@localhost /]#  service mysql restart

7. 登陆，修改密码

密码：第4步初始化数据库随机生成得密码，输入密码不显示。

[root@VM_0_3_centos support-files]# service mysql start
Starting MySQL.. SUCCESS! 
[root@VM_0_3_centos support-files]# mysql -uroot -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 82
Server version: 8.0.20
Copyright (c) 2000, 2020, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> alter user 'root'@'localhost' identified by 'kid+1412';
Query OK, 0 rows affected (0.01 sec)
mysql>

Linux下安装mysql8.0.20 - 图7

8. 开启Navicat远程连接

# 登录
[root@VM_0_3_centos support-files]# mysql -uroot -p 
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2582
Server version: 8.0.20 MySQL Community Server - GPL
Copyright (c) 2000, 2020, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
# 选择mysql数据库
mysql> use mysql
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
# 查看用户信息
mysql> select host, user, authentication_string, plugin from user;
+-----------+------------------+------------------------------------------------------------------------+-----------------------+
| host      | user             | authentication_string                                                  | plugin                |
+-----------+------------------+------------------------------------------------------------------------+-----------------------+
| localhost | mysql.infoschema | $A$005$THISISACOMBINATIONOFINVALIDSALTANDPASSWORDTHATMUSTNEVERBRBEUSED | caching_sha2_password |
| localhost | mysql.session    | $A$005$THISISACOMBINATIONOFINVALIDSALTANDPASSWORDTHATMUSTNEVERBRBEUSED | caching_sha2_password |
| localhost | mysql.sys        | $A$005$THISISACOMBINATIONOFINVALIDSALTANDPASSWORDTHATMUSTNEVERBRBEUSED | caching_sha2_password |
| localhost | root             | $A$005$=!..iRO=k:x_>qiFtXTYJmwgur/2pJH1mfk26FBL.1YZOC.YcBw8auuFFM0 | caching_sha2_password |
+-----------+------------------+------------------------------------------------------------------------+-----------------------+
4 rows in set (0.00 sec)
# 更新root信息
mysql> update user set host = '%' where user = 'root';
Query OK, 1 row affected (0.02 sec)
Rows matched: 1  Changed: 1  Warnings: 0
# 授权root用户可以远程登陆，失败
mysql> GRANT ALL ON *.* TO 'root'@'%';
ERROR 1410 (42000): You are not allowed to create a user with GRANT
# 立即生效，重新授权
mysql> flush privileges; 
Query OK, 0 rows affected (0.02 sec)
# 授权root用户可以远程登陆
mysql> GRANT ALL ON *.* TO 'root'@'%';
Query OK, 0 rows affected (0.02 sec)
# 立即生效
mysql> flush privileges;
Query OK, 0 rows affected (0.01 sec)
# 
mysql> alter user 'root'@'%' identified with mysql_native_password by 'kid+1412';
Query OK, 0 rows affected (0.01 sec)
# 立即生效
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)
# 退出
mysql> exit

9.navicat连接成功

Linux下安装mysql8.0.20 - 图8

定时备份

#!/bin/bash
#保存备份个数，备份31天数据
number=31
#备份保存路径
backup_dir=/app/databack/database
#日期
dd=`date +%Y-%m-%d-%H-%M-%S`
#备份工具
tool=mysqldump
#用户名
username=root
#密码
password=123456
#将要备份的数据库
database_name=ry
#如果文件夹不存在则创建
if [ ! -d $backup_dir ];
then
    mkdir -p $backup_dir;
fi
#简单写法  mysqldump -u root -p123456 users > /root/mysqlbackup/users-$filename.sql
$tool -u $username -p$password $database_name > $backup_dir/$database_name-$dd.sql
#写创建备份日志
echo "create $backup_dir/$database_name-$dd.dupm" >> $backup_dir/log.txt
#找出需要删除的备份
delfile=`ls -l -crt  $backup_dir/*.sql | awk '{print $9 }' | head -1`
#判断现在的备份数量是否大于$number
count=`ls -l -crt  $backup_dir/*.sql | awk '{print $9 }' | wc -l`
if [ $count -gt $number ]
then
  #删除最早生成的备份，只保留number数量的备份
  rm $delfile
  #写删除文件日志
  echo "delete $delfile" >> $backup_dir/log.txt
fi

启动定时任务

查看定时任务

crondtab -l

编辑定时任务

crontab -u root -e

输入：

00 03 * * * /app/databack/mysql_back.sh
:wq

Linux下安装mysql8.0.20