[root@localhost ~]# systemctl stop mariadb.service
[root@localhost ~]# systemctl disable mariadb.service
Removed symlink /etc/systemd/system/multi-user.target.wants/mariadb.service.
[root@localhost ~]# rpm -qa | grep mariadb
mariadb-server-5.5.68-1.el7.x86_64
mariadb-5.5.68-1.el7.x86_64
mariadb-libs-5.5.68-1.el7.x86_64
##########################删除数据，危险操作
[root@localhost ~]# rm -rf /var/lib/mysql/*
[root@localhost ~]# rpm -e mariadb-server mariadb mariadb-libs  postfix  perl-DBD-MySQL

[root@localhost ~]# ll
total 1087504
-rw-------. 1 root root       1243 Dec  5 13:48 anaconda-ks.cfg
-rw-r--r--  1 root root 1113600000 Dec  9 13:51 mysql-8.4.7-1.el7.x86_64.rpm-bundle.tar

[root@localhost ~]# sudo yum install openssl-devel
[root@localhost ~]# yum install perl-JSON
[root@localhost ~]# yum install perl-Test-Simple
[root@localhost ~]# tar xf mysql-8.4.7-1.el7.x86_64.rpm-bundle.tar
[root@localhost ~]# rpm -ivh *.rpm

[root@localhost ~]# chown mysql:mysql -R  /var/lib/mysql
[root@localhost ~]# systemctl start mysqld
[root@localhost ~]# systemctl enable mysqld
######查看初始密码，，密码是root@localhost: 后面的内容
[root@localhost ~]# cat /var/log/mysqld.log | grep password
2025-12-09T06:07:14.525458Z 6 [Note] [MY-010454] [Server] A temporary password is generated for root@localhost: &=FHdIdiU4q;

###修改密码
[root@localhost ~]# mysql -uroot -p
Enter password: 
mysql>  ALTER USER `root`@`localhost` IDENTIFIED WITH  caching_sha2_password  BY '123456';
Query OK, 0 rows affected (0.00 sec)

mysql>  create database dolphinscheduler DEFAULT CHARACTER SET utf8 ;
mysql> CREATE USER  'dolphinscheduler'@'%'   identified by 'dolphinscheduler#321';
Query OK, 0 rows affected (0.01 sec)
mysql> grant all  PRIVILEGES ON dolphinscheduler.* TO 'dolphinscheduler'@'%' WITH GRANT OPTION ;
Query OK, 0 rows affected (0.01 sec)
mysql> FLUSH PRIVILEGES;
Query OK, 0 rows affected (0.00 sec)