CentOS7.7 安装mysql8.0.27

1. 删除 mariadb
    rpm -qa | grep mariadb
        mariadb-libs-5.5.68-1.el7.x86_64 // 这只是示例返回值 具体看服务器
    rpm -e --nodeps mariadb-libs


2. 安装mysql8.0.27 rpm

    tar xvf mysql-8.0.27-1.el7.x86_64.rpm-bundle.tar    

    解压缩之后，包含以下rpm包
    mysql-community-client-8.0.27-1.el7.x86_64.rpm
    mysql-community-client-plugins-8.0.27-1.el7.x86_64.rpm
    mysql-community-common-8.0.27-1.el7.x86_64.rpm
    mysql-community-devel-8.0.27-1.el7.x86_64.rpm
    mysql-community-embedded-compat-8.0.27-1.el7.x86_64.rpm
    mysql-community-libs-8.0.27-1.el7.x86_64.rpm
    mysql-community-libs-compat-8.0.27-1.el7.x86_64.rpm
    mysql-community-server-8.0.27-1.el7.x86_64.rpm
    mysql-community-test-8.0.27-1.el7.x86_64.rpm

    安装所有的rpm包
    rpm -ivh mysql-community-common-8.0.27-1.el7.x86_64.rpm
    rpm -ivh mysql-community-client-plugins-8.0.27-1.el7.x86_64.rpm
    rpm -ivh mysql-community-libs-8.0.27-1.el7.x86_64.rpm
    rpm -ivh mysql-community-client-8.0.27-1.el7.x86_64.rpm
    rpm -ivh mysql-community-server-8.0.27-1.el7.x86_64.rpm  --force --nodeps

    rpm -ivh mysql-community-libs-compat-8.0.27-1.el7.x86_64.rpm
    rpm -ivh mysql-community-embedded-compat-8.0.27-1.el7.x86_64.rpm
    rpm -ivh mysql-community-devel-8.0.27-1.el7.x86_64.rpm --force --nodeps
    rpm -ivh mysql-community-test-8.0.27-1.el7.x86_64.rpm --force --nodeps

    错误1
    warning: mysql-community-client-8.0.27-1.el7.x86_64.rpm: Header V3 DSA/SHA256 Signature, key ID 5072e1f5: NOKEY
    error: Failed dependencies:
        pkgconfig(openssl) is needed by mysql-community-devel-8.0.27-1.el7.x86_64

    解决方案
        rpm -ivh openssl-devel-1.0.2k-19.el7.x86_64.rpm openssl-1.0.2k-19.el7.x86_64.rpm  --force --nodeps



    错误2
    warning: mysql-community-server-8.0.27-1.el7.x86_64.rpm: Header V3 DSA/SHA256 Signature, key ID 5072e1f5: NOKEY
    error: Failed dependencies:
        /usr/bin/perl is needed by mysql-community-server-8.0.27-1.el7.x86_64
        net-tools is needed by mysql-community-server-8.0.27-1.el7.x86_64
        perl(Getopt::Long) is needed by mysql-community-server-8.0.27-1.el7.x86_64
        perl(strict) is needed by mysql-community-server-8.0.27-1.el7.x86_64
    解决方案
        rpm -ivh OpenIPMI-perl-2.0.27-1.el7.x86_64.rpm perl-JSON-2.59-2.el7.noarch.rpm perl-devel-5.16.3-297.el7.x86_64.rpm autoconf-2.69-11.el7.noarch.rpm --force --nodeps

3. 安装mysql8.0.27命令
    mysqld --initialize --console

    chown -R mysql:mysql /var/lib/mysql/

    启动mysql服务
    命令：systemctl start mysqld
    命令：systemctl status mysqld

    查看临时密码：
    命令：cat /var/log/mysqld.log | grep password

    关闭防火墙(用于远程连接)
    systemctl stop firewalld

4. mysql 内部命令
    1.改密码
    alter user 'root'@'localhost' identified with mysql_native_password by 'root';
    flush privileges;

    2.开启远程连接
    use mysql;
    update user set host='%' where user='root'; //任意ip都可以连
    update user set host='your ip' where user='root'; //指定ip
    flush privileges;