MySQL数据库安装配置
1、检查是否已经安装MySQL,执行命令
rpm -qa | grep mysql2、删除已经安装的mysql
rpm -e --nodeps
rpm -e --nodeps
rpm -e --nodeps3、再次执行查询命令，查看是否删除
rpm -qa | grep mysql4、查询mysql对应的文件夹
whereis mysql
find / -name mysql5、删除相关目录或文件
rm -rf /usr/bin/mysql /usr/include/mysql /data/mysql /data/mysql/mysql6、验证是否删除完毕
whereis mysql
find / -name mysql7、检查mysql用户组和用户是否存在，如果没有，则创建
cat /etc/group | grep mysql
cat /etc/passwd | grep mysql
groupadd mysql
useradd -r -g mysql mysql8、yum方式安装MySQL5.7
(1)下载并安装MySQL官方的 Yum Repository
1)下载并上传
https://dev.mysql.com/downloads/repo/yum/
mysql80-community-release-el7-3.noarch.rpm2)安装rpm
# rpm -ivh mysql80-community-release-el7-3.noarch.rpm3)查看MySQL版本
默认是mysql8.0版本
# yum list|grep mysql4)修改安装MySQL版本
更改安装版本
# vim /etc/yum.repos.d/mysql-community.repo
把8.0的enabled=1 改为enabled=0
把需要安装的版本enabled=0 改为enabled=1
再查看安装版本
# yum list | grep mysql扫描二维码关注公众号，回复： 8721711 查看本文章
5)安装MySQL
yum install mysql
// 这里说明一下
/**
我本来有mysql5.6
MySQL-server-5.6.37-1.el7.x86_64
MySQL-devel-5.6.37-1.el7.x86_64
MySQL-shared-5.6.37-1.el6.x86_64
MySQL-client-5.6.37-1.el7.x86_64
*/
// 可是要求是mysql5.7
/**
于是乎又下载的
mysql-5.7.28-linux-glibc2.12-x86_64.tar.gz
可是安装出了很多错误
跟一运维老哥说了这情况，他说这是二进制版本
安装起来有些麻烦，并让我yum安装
*/
// 然后呐，用yum安装的，也花了很大一部分时间，幸运的是，成功了
// PS: 二进制版本安装有一哥们写的不错，访问量3W+
// 但是这是后来发现的，所以就没去尝试
// 链接贴这了
https://blog.csdn.net/z13615480737/article/details/80019881
6)查看是否安装成功
# rpm -qa | grep mysql
mysql-community-common-5.7.28-1.el7.x86_64
mysql-community-libs-5.7.28-1.el7.x86_64
mysql80-community-release-el7-3.noarch
mysql-community-server-5.7.28-1.el7.x86_64
mysql-community-client-5.7.28-1.el7.x86_64
(2)MySQL数据库设置
首先启动MySQL
# systemctl start mysqld.service
查看MySQL运行状态
# systemctl status mysqld.service(3)此时MySQL已经开始正常运行，不过要想进入MySQL还得先找出此时root用户的密码，
通过如下命令可以在日志文件中找出密码：
# grep "password" /var/log/mysqld.log
6o/Q85u/cz4_(4)如下命令进入数据库：
# mysql -uroot -p
输入初始密码，此时不能做任何事情，因为MySQL默认必须修改密码之后才能操作数据库：
mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY '在此输入新密码';
这里有个问题，新密码设置的时候如果设置的过于简单会报错：
mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY 'new password';
ERROR 1819 (HY000): Your password does not satisfy the current policy requirements原因是因为MySQL有密码设置的规范，具体是与validate_password_policy的值有关：
MySQL完整的初始密码规则可以通过如下命令查看：
mysql> SHOW VARIABLES LIKE 'validate_password%';
可能查看不了
mysql> SHOW VARIABLES LIKE 'validate_password%';
ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.看它意思是要重新设置密码
mysql> SET PASSWORD = PASSWORD('123456');
ERROR 1819 (HY000): Your password does not satisfy the current policy requirements
虽然继续报错，但是没关系
mysql> set global validate_password_policy=0;
Query OK, 0 rows affected (0.01 sec)mysql>
mysql> set global validate_password_length=1;
Query OK, 0 rows affected (0.00 sec)mysql>
mysql> SET PASSWORD = PASSWORD('toor');
Query OK, 0 rows affected, 1 warning (0.00 sec)到这成功了！
退出以后重新登录
# mysql -uroot -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 3
Server version: 5.7.28 MySQL Community Server (GPL)Copyright (c) 2000, 2019, 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> SHOW VARIABLES LIKE 'validate_password%';
+--------------------------------------+-------+
| Variable_name | Value |
+--------------------------------------+-------+
| validate_password_check_user_name | OFF |
| validate_password_dictionary_file | |
| validate_password_length | 4 |
| validate_password_mixed_case_count | 1 |
| validate_password_number_count | 1 |
| validate_password_policy | LOW |
| validate_password_special_char_count | 1 |
+--------------------------------------+-------+
7 rows in set (0.00 sec)# MySQL完整的初始密码规则已经通过如上命令查看出来
(5)Linux下允许MySQL 授权远程连接
1)登录mysql数据库
mysql -u root -p (root)用户名2)创建用户用来远程连接
mysql> GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY 'root' WITH GRANT OPTION;
（root表示用户名，%表示所有的电脑都可以连接，也可以设置某个ip地址运行连接，root表示密码）3)执行 flush privileges;命令立即生效
mysql> flush privileges;4)如果此时还无法连接，检测配置文件（/etc/mysql/mysql.conf.d/mysqld.cnf）
cat /etc/mysql/mysql.conf.d/mysqld.cnf
vim /etc/mysql/mysql.conf.d/mysqld.cnfbind-address配置是否开启，应该是关闭
#bind-address = 127.0.0.1 注释掉；
key_buffer_size = 16M
max_allowed_packet = 16M
thread_stack = 192K
thread_cache_size = 85)重启mysql并查看状态
systemctl stop mysqld
systemctl status mysqld
systemctl start mysqld
systemctl status mysqld6)然后再本地远程linux下mysql数据库
C:\Users\admin>mysql -h 192.168.2.6 -u root -p
Enter password: ****
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 11
Server version: 5.7.28 MySQL Community Server (GPL)Copyright (c) 2000, 2015, 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> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| sys |
+--------------------+
4 rows in set (0.00 sec)
7)查看linux下mysql安装目录
mysql> show variables like '%dir%';
+-----------------------------------------+----------------------------+
| Variable_name | Value |
+-----------------------------------------+----------------------------+
| basedir | /usr/ |
| binlog_direct_non_transactional_updates | OFF |
| character_sets_dir | /usr/share/mysql/charsets/ |
| datadir | /var/lib/mysql/ |
| ignore_db_dirs | |
| innodb_data_home_dir | |
| innodb_log_group_home_dir | ./ |
| innodb_max_dirty_pages_pct | 75.000000 |
| innodb_max_dirty_pages_pct_lwm | 0.000000 |
| innodb_tmpdir | |
| innodb_undo_directory | ./ |
| lc_messages_dir | /usr/share/mysql/ |
| plugin_dir | /usr/lib64/mysql/plugin/ |
| slave_load_tmpdir | /tmp |
| tmpdir | /tmp |
+-----------------------------------------+----------------------------+
15 rows in set (0.00 sec)8)查询数据库的用户
mysql> SELECT DISTINCT CONCAT('User: ''',user,'''@''',host,''';') AS query FROM mysql.user;
+------------------------------------+
| query |
+------------------------------------+
| User: 'root'@'%'; |
| User: 'mysql.session'@'localhost'; |
| User: 'mysql.sys'@'localhost'; |
| User: 'root'@'localhost'; |
+------------------------------------+
4 rows in set (0.01 sec)9)查看MySQL数据库状态，关闭mysqld服务
[root@ha156_master ~]# systemctl status mysqld
● mysqld.service - MySQL Server
Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)
Active: active (running) since 三 2019-11-20 15:59:06 CST; 28min ago
Docs: man:mysqld(8)
http://dev.mysql.com/doc/refman/en/using-systemd.html
Process: 19504 ExecStart=/usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid $MYSQLD_OPTS (code=exited, status=0/SUCCESS)
Process: 19480 ExecStartPre=/usr/bin/mysqld_pre_systemd (code=exited, status=0/SUCCESS)
Main PID: 19507 (mysqld)
Tasks: 30
CGroup: /system.slice/mysqld.service
└─19507 /usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid11月 20 15:59:04 ha156_master systemd[1]: Starting MySQL Server...
11月 20 15:59:06 ha156_master systemd[1]: Started MySQL Server.
[root@ha156_master ~]#
[root@ha156_master ~]# systemctl stop mysqld
[root@ha156_master ~]#
[root@ha156_master ~]# systemctl status mysqld
● mysqld.service - MySQL Server
Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)
Active: inactive (dead) since 三 2019-11-20 16:27:45 CST; 3s ago
Docs: man:mysqld(8)
http://dev.mysql.com/doc/refman/en/using-systemd.html
Process: 19504 ExecStart=/usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid $MYSQLD_OPTS (code=exited, status=0/SUCCESS)
Process: 19480 ExecStartPre=/usr/bin/mysqld_pre_systemd (code=exited, status=0/SUCCESS)
Main PID: 19507 (code=exited, status=0/SUCCESS)11月 20 15:59:04 ha156_master systemd[1]: Starting MySQL Server...
11月 20 15:59:06 ha156_master systemd[1]: Started MySQL Server.
11月 20 16:27:41 ha156_master systemd[1]: Stopping MySQL Server...
11月 20 16:27:45 ha156_master systemd[1]: Stopped MySQL Server.
[root@ha156_master ~]#
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