1.配置

系统：centos7.6

mysql版本：mysql 5.7

2.这里原先的方案为：直接卸载mysql

3.遇到的问题：

安装mysql的最后一步时

#yum install mysql-community-server

遇到以下错误：

Error: Package: 2:postfix-2.10.1-7.el7.x86_64 (@anaconda)

Requires: libmysqlclient.so.18(libmysqlclient_18)(64bit)

Removing: 1:mariadb-libs-5.5.60-1.el7_5.x86_64 (@anaconda)

libmysqlclient.so.18(libmysqlclient_18)(64bit)

Obsoleted By: mysql-community-libs-5.7.29-1.el6.x86_64 (mysql57-community-dmr)

Not found

Updated By: 1:mariadb-libs-5.5.64-1.el7.x86_64 (base)

libmysqlclient.so.18(libmysqlclient_18)(64bit)

Error: Package: 2:postfix-2.10.1-7.el7.x86_64 (@anaconda)

Requires: libmysqlclient.so.18()(64bit)

Removing: 1:mariadb-libs-5.5.60-1.el7_5.x86_64 (@anaconda)

libmysqlclient.so.18()(64bit)

Obsoleted By: mysql-community-libs-5.7.29-1.el6.x86_64 (mysql57-community-dmr)

~libmysqlclient.so.20()(64bit)

Updated By: 1:mariadb-libs-5.5.64-1.el7.x86_64 (base)

libmysqlclient.so.18()(64bit)

Error: Package: mysql-community-server-5.7.29-1.el6.x86_64 (mysql57-community-dmr)

Requires: libsasl2.so.2()(64bit)

You could try using --skip-broken to work around the problem

You could try running: rpm -Va --nofiles --nodigest

查询各种信息；基本确定是因为 mysql 的依赖问题。刚开始，最快的解决方案就是卸载重装.

4.解决方法：

卸载，重装了两遍还是出现同样的错误。

提示：

Error: Package: mysql-community-server-5.7.29-1.el6.x86_64 (mysql57-community-dmr)

Requires: libsasl2.so.2()(64bit)

You could try using --skip-broken to work around the problem

You could try running: rpm -Va --nofiles --nodigest

最后解决方案：

修改vim /etc/yum.repos.d/mysql-community.repo 源文件

这里注意，禁用mysql其他版本，只启用5.7

更改2点，保存后重新安装

enabled=0

gpgcheck=0

yum install mysql-community-server

以上操作完成后，完美解决

下面来说说如何卸载

4.1.快速删除

yum  remove  mysql mysql-server mysql-libs mysql-server

4.2.查找残留文件

rpm -qa | grep -i mysql

4.3将查询出来的文件逐个删除，如：

yum remove mysql-community-common-5.7.29-1.el6.x86_64

4.4.查找残留目录

whereis mysql

4.5逐条删除目录，如：

rm –rf /usr/lib64/mysql

####这些操作完成后更新源

5.给CentOS添加rpm源，并且选择较新的源

wget dev.mysql.com/get/mysql-community-release-el6-5.noarch.rpm   --no-check-certificate

yum localinstall mysql-community-release-el6-5.noarch.rpm

yum repolist all | grep mysql

yum-config-manager --disable mysql55-community

yum-config-manager --disable mysql56-community

yum-config-manager --enable mysql57-community-dmr

yum repolist enabled | grep mysql

6.查询mysql所用的版本：

yum repolist all | grep mysql

7.检测系统是否存在mysql

yum list installed|grep mysql

8.删除mysql依赖项

yum-yremovemysql-libs.x86_64

9.备注：需要掌握的yum命令

9.1安装yum 仓库列表：

yum -y   localinstall mysql57-community-release-el6-8.noarch.rpm

9.2查看：

yum list | grep mysql

9.3安装mysql

yum -y install mysql-community-server

10.如何禁用或启用mysql的其他版本：

方法1:

官网文档上给出的执行命令

yum-config-manager --disable mysql56-community

yum-config-manager --enable mysql57-community

方法2：修改配置文件

vi /etc/yum.repos.d/mysql-community.repo

修改完成后再次查看：yum repolist all | grep mysql

原文：https://www.cnblogs.com/suesky/p/12767313.html