LNMP 之 安裝mysql

清理原有mysql

rpm -qa | grep mysql
#可能的顯示情況如下
#mysql-community-libs-8.0.12-1.el7.x86_64
#mysql80-community-release-el7-1.noarch
#mysql-community-client-8.0.12-1.el7.x86_64
#mysql-community-common-8.0.12-1.el7.x86_64
#mysql-community-server-8.0.12-1.el7.x86_64
#通過下面的命令進行刪除
yum remove mysql-xxx-xxx-
#查找mysql的相關文件
find / -name mysql
#根據自身的需求刪除mysql的配置文件信息
rm -rf /var/lib/mysql

刪除CentOS7默認的數據庫mariadb

rpm -qa | grep mariadb
#查找mariadb
#可能出現的結果mariadb-libs-5.5.56-2.el7.x86_64
#將查找出來的結果進行強制刪除
rpm -e --nodeps mariadb-libs-5.5.56-2.el7.x86_64

下載mysql yum源

##下載yum源repo 下載
cd /usr/src
wget https://dev.mysql.com/get/mysql80-community-release-el7-1.noarch.rpm
#安裝yum源
yum localinstall mysql80-community-release-el7-1.noarch.rpm

 ##下載rpm包直接安裝
 wget XXX
 tar xvzf XXX
 rpm -ivh XXX

#更新yum源
yum clean all
yum makecache

#開始安裝MySQL
yum install mysql-community-server

#啓動MySQL
systemctl start mysqld

#啓動成功後可以查看初始化密碼隨機生成的
cat /var/log/mysqld.log | grep password

#登錄MySQL修改mysql用戶密碼
mysql -u root -p
mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY 'yourpassword';
#遠程設置
mysql> use mysql;
mysql> update user set host='%' where user='root';
#授權用戶名的權限，賦予任何主機訪問數據的權限
mysql> GRANT ALL PRIVILEGES ON *.* TO 'root'@'%'WITH GRANT OPTION;
mysql> FLUSH PRIVILEGES;

其他的幾種mysql用戶權限的設置方法

#允許myuser用戶使用mypassword密碼從任何主機連接到mysql服務器
GRANT ALL PRIVILEGES ON *.* TO 'myuser'@'%'IDENTIFIED BY 'mypassword' WITH GRANT OPTION;
#允許用戶myuser從ip爲192.168.1.6的主機連接到mysql服務器，並使用mypassword作爲密碼
GRANT ALL PRIVILEGES ON *.* TO 'myuser'@'192.168.1.3'IDENTIFIED BY 'mypassword' WITH GRANT OPTION;

數據庫的服務操作

#啓動mysql
systemctl start mysqld.service
#結束
systemctl stop mysqld.service
#重啓
systemctl restart mysqld.service 
#開機自啓
systemctl enable mysqld.service

修改mysql密碼策略

mysql> set global validate_password_policy=0;  
mysql> set global validate_password_mixed_case_count=0;  
mysql> set global validate_password_number_count=3;  
mysql> set global validate_password_special_char_count=0;  
mysql> set global validate_password_length=3;  

  
    alter user 'root'@'localhost' identified by 'newpassword';

mysql> SHOW VARIABLES LIKE 'validate_password%';  
+--------------------------------------+-------+  
| Variable_name                        | Value |  
+--------------------------------------+-------+  
| validate_password_dictionary_file    |       |  
| validate_password_length             | 3     |  
| validate_password_mixed_case_count   | 0     |  
| validate_password_number_count       | 3     |  
| validate_password_policy             | LOW   |  
| validate_password_special_char_count | 0     |  
+--------------------------------------+-------+  
6 rows in set (0.00 sec)  
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