1、查看mysql是否安裝
首先我們需要查看軟件是否已經安裝，或者說查看安裝的軟件包名稱。如查找是否安裝mysql
rpm -qa | grep mysql
2、卸載查到的軟件
rpm -e --nodeps mysql-community-release-el7-5.noarch
3、下載mysql的repo源
wget http://repo.mysql.com/mysql-community-release-el7-5.noarch.rpm
4、安裝mysql源
rpm -ivh mysql-community-release-el7-5.noarch.rpm
如果出現下面報錯：
error: Failed dependencies: mysql-community-release conflicts with (installed) mysql57-community-release-el7-10.noarch
解決方式，添加如下參數：
rpm -ivh mysql-community-release-el7-5.noarch.rpm --nodeps --force
5、開始安裝mysql數據庫
yum install mysql-server -y
如果出現如下報錯：
2021-11-07T03:06:04.715107Z 0 [ERROR] [MY-010460] [Server] --initialize specified but the data directory exists and is not writable. Aborting.
2021-11-07T03:06:04.715141Z 0 [ERROR] [MY-013236] [Server] The designated data directory /var/lib/mysql/ is unusable. You can remove all files that the server added to it.
2021-11-07T03:06:04.715203Z 0 [ERROR] [MY-010119] [Server] Aborting
解決方式：
chown -R mysql:mysql /var/lib/mysql
6、重啟服務
service mysqld restart
7、登錄mysql數據庫
mysql -u root -p
注意
第一次使用數據庫登錄的時候不用輸入密碼，因為還沒有設置密碼，直接回車進入數據庫后再去修改密碼.