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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