#1. 卸载原来的数据库

1.1 查询所安装的MariaDB组件：

[root@localhost logs]# rpm -qa | grep
Maria*

MariaDB-server-5.5.49-1.el7.centos.x86_64

MariaDB-common-5.5.49-1.el7.centos.x86_64

MariaDB-client-5.5.49-1.el7.centos.x86_64

1.2 卸载数据库：

[root@localhost logs]# yum -y remove mari*

1.3 删除数据库文件：

[root@localhost logs]# rm -rf
/var/lib/mysql/*

2. 安装mysql5.7

2.1 下载解压Mysql

```

wget
https://obs.cn-north-4.myhuaweicloud.com/obs-mirror-ftp4/database/mysql-5.7.27-aarch64.tar.gz

tar xvf
mysql-5.7.27-aarch64.tar.gz

mv
/usr/local/mysql-5.7.27-aarch64 /usr/local/mysql

```

2.2 创建相关依赖

```

mkdir -p
/usr/local/mysql/logs //创建logs目录

ln -sf
/usr/local/mysql/my.cnf /etc/my.cnf

cp -rf
/usr/local/mysql/extra/lib* /usr/lib64/

mv /usr/lib64/libstdc++.so.6
/usr/lib64/libstdc++.so.6.old

ln -s
/usr/lib64/libstdc++.so.6.0.24 /usr/lib64/libstdc++.so.6

```

2.3 创建mysql组

```

groupadd mysql

useradd -g mysql mysql

chown -R mysql:mysql
/usr/local/mysql

```

2.4 设置开机启动

```

cp -rf
/usr/local/mysql/support-files/mysql.server /etc/init.d/mysqld

chmod +x
/etc/init.d/mysqld

systemctl enable mysqld

```

2.5 添加环境变量

/etc/profile添加下面两行代码：

```

export
MYSQL_HOME=/usr/local/mysql

export
PATH=$PATH:$MYSQL_HOME/bin

```

source /etc/profile

2.6 启动mysql

初始化mysql

mysqld
–initialize-insecure --user=mysql --basedir=/usr/local/mysql
–datadir=/usr/local/mysql/data

开启mysql

systemctl start mysqld

查看状态

systemctl status mysqld

2.7 修改密码

mysql -u KaTeX parse error: Undefined control sequence: \* at position 42: …PRIVILEGES ON  \̲*̲.\* TO 'root'@'…mysql_password’;flush privileges;"

mysql -u $mysql\_user-e"updatemysql.usersetauthentication\_string=password{(}^{\prime }$mysql_password’)
where user=‘root’ and host=‘localhost’;flush privileges;"

3. 重新初始化数据库

需要预创建的数据库重新创建，比如初始化scm库

scm_prepare_database.sh mysql scm scm xxx