本次将在Linux下通过yum安装MySQL，安装的版本为MySQL 5.7，官网中是最新版本8.0，在网上查了下，发现最新版本的yum源也包含了旧版本，而我们，只需要在安装时启用 5.7 的安装即可。

本人环境：CentOS 7.3 64位

1.检查CentOS是否有系统自带的mysql

yum list installed | grep mysql

如果存在系统自带的mysql及依赖，则通过yum remove将其卸载

2.在官网中获取yum源

这里获取到的是最新版本的下载地址：https://dev.mysql.com/get/mysql80-community-release-el7-3.noarch.rpm

3.CentOS中下载rpm包，并安装本地mysql源

下载rpm包：wgethttps://dev.mysql.com/get/mysql80-community-release-el7-3.noarch.rpm--no-check-certificate
安装mysql源：yum localinstall mysql80-community-release-el7-3.noarch.rpm

通过yum localinstall安装mysql源，可以帮助我们解决本地rpm包的依赖问题。

最后，验证是否安装成功：yum repolist all | grep mysql

4.修改默认安装版本为5.7

从上面的图片，我们可以看到，默认是MySQL 8.0可用，我们若想安装MySQL 5.7，则需启用5.7。接下来通过直接修改配置文件来设置启用。

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

输入上面的命令，在编辑界面，先输入i进入编辑模式，将8.0的enabled设置为0，将5.7的enabled设置为1，如下：

接着按Esc退出编辑模式，最后输入:wq保存并退出。

再次输入命令：yum repolist all | grep mysql，可以看到8.0已被禁用，而5.7是启用的。

5.安装MySQL

yum install mysql-community-server

输入上面命令，进行安装即可。

点我复制[root@wintestmysql]#yuminstallmysql-community-serverLoadedplugins:fastestmirrorLoadingmirrorspeedsfromcachedhostfileResolvingDependencies-->Runningtransactioncheck--->Packagemysql-community-server.x86_640:5.7.27-1.el7willbeinstalled-->ProcessingDependency:mysql-community-common(x86-64)=5.7.27-1.el7forpackage:mysql-community-server-5.7.27-1.el7.x86_64-->ProcessingDependency:mysql-community-client(x86-64)>=5.7.9forpackage:mysql-community-server-5.7.27-1.el7.x86_64-->ProcessingDependency:libaio.so.1(LIBAIO_0.4)(64bit)forpackage:mysql-community-server-5.7.27-1.el7.x86_64-->ProcessingDependency:libaio.so.1(LIBAIO_0.1)(64bit)forpackage:mysql-community-server-5.7.27-1.el7.x86_64-->ProcessingDependency:libaio.so.1()(64bit)forpackage:mysql-community-server-5.7.27-1.el7.x86_64-->Runningtransactioncheck--->Packagelibaio.x86_640:0.3.109-13.el7willbeinstalled--->Packagemysql-community-client.x86_640:5.7.27-1.el7willbeinstalled-->ProcessingDependency:mysql-community-libs(x86-64)>=5.7.9forpackage:mysql-community-client-5.7.27-1.el7.x86_64--->Packagemysql-community-common.x86_640:5.7.27-1.el7willbeinstalled-->Runningtransactioncheck--->Packagemariadb-libs.x86_641:5.5.52-1.el7willbeobsoleted-->ProcessingDependency:libmysqlclient.so.18()(64bit)forpackage:2:postfix-2.10.1-6.el7.x86_64-->ProcessingDependency:libmysqlclient.so.18(libmysqlclient_18)(64bit)forpackage:2:postfix-2.10.1-6.el7.x86_64--->Packagemysql-community-libs.x86_640:5.7.27-1.el7willbeobsoleting-->Runningtransactioncheck--->Packagemysql-community-libs-compat.x86_640:5.7.27-1.el7willbeobsoleting--->Packagepostfix.x86_642:2.10.1-6.el7willbeupdated--->Packagepostfix.x86_642:2.10.1-7.el7willbeanupdate-->FinishedDependencyResolutionDependenciesResolved====================================================================================PackageArchVersionRepositorySize====================================================================================Installing:mysql-community-libsx86_645.7.27-1.el7mysql57-community2.2Mreplacingmariadb-libs.x86_641:5.5.52-1.el7mysql-community-libs-compatx86_645.7.27-1.el7mysql57-community2.0Mreplacingmariadb-libs.x86_641:5.5.52-1.el7mysql-community-serverx86_645.7.27-1.el7mysql57-community165MInstallingfordependencies:libaiox86_640.3.109-13.el7base24kmysql-community-clientx86_645.7.27-1.el7mysql57-community24Mmysql-community-commonx86_645.7.27-1.el7mysql57-community275kUpdatingfordependencies:postfixx86_642:2.10.1-7.el7base2.4MTransactionSummary====================================================================================Install3Packages(+3Dependentpackages)Upgrade(1Dependentpackage)Totaldownloadsize:197MIsthisok[y/d/N]:yDownloadingpackages:DeltaRPMsdisabledbecause/usr/bin/applydeltarpmnotinstalled.(1/7):libaio-0.3.109-13.el7.x86_64.rpm|24kB00:00:00warning:/var/cache/yum/x86_64/7/mysql57-community/packages/mysql-community-common-5.7.27-1.el7.x86_64.rpm:HeaderV3DSA/SHA1Signature,keyID5072e1f5:NOKEYPublickeyformysql-community-common-5.7.27-1.el7.x86_64.rpmisnotinstalled(2/7):mysql-community-common-5.7.27-1.el7.x86_64.rpm|275kB00:00:01(3/7):mysql-community-libs-5.7.27-1.el7.x86_64.rpm|2.2MB00:00:01(4/7):mysql-community-libs-compat-5.7.27-1.el7.x86_64.rpm|2.0MB00:00:01(5/7):postfix-2.10.1-7.el7.x86_64.rpm|2.4MB00:00:00(6/7):mysql-community-client-5.7.27-1.el7.x86_64.rpm|24MB00:00:34(7/7):mysql-community-server-5.7.27-1.el7.x86_64.rpm|165MB00:00:52------------------------------------------------------------------------------------Total3.5MB/s|197MB00:56Retrievingkeyfromfile:///etc/pki/rpm-gpg/RPM-GPG-KEY-mysqlImportingGPGkey0x5072E1F5:Userid:"MySQLReleaseEngineering<mysql-build@oss.oracle.com>"Fingerprint:a4a9406876fcbd3c456770c88c718d3b5072e1f5Package:mysql80-community-release-el7-3.noarch(installed)From:/etc/pki/rpm-gpg/RPM-GPG-KEY-mysqlIsthisok[y/N]:yRunningtransactioncheckRunningtransactiontestTransactiontestsucceededRunningtransactionInstalling:mysql-community-common-5.7.27-1.el7.x86_641/9Installing:mysql-community-libs-5.7.27-1.el7.x86_642/9Installing:mysql-community-libs-compat-5.7.27-1.el7.x86_643/9Installing:mysql-community-client-5.7.27-1.el7.x86_644/9Installing:libaio-0.3.109-13.el7.x86_645/9Installing:mysql-community-server-5.7.27-1.el7.x86_646/9Updating:2:postfix-2.10.1-7.el7.x86_647/9Cleanup:2:postfix-2.10.1-6.el7.x86_648/9Erasing:1:mariadb-libs-5.5.52-1.el7.x86_649/9Verifying:mysql-community-libs-compat-5.7.27-1.el7.x86_641/9Verifying:mysql-community-common-5.7.27-1.el7.x86_642/9Verifying:mysql-community-libs-5.7.27-1.el7.x86_643/9Verifying:2:postfix-2.10.1-7.el7.x86_644/9Verifying:mysql-community-server-5.7.27-1.el7.x86_645/9Verifying:mysql-community-client-5.7.27-1.el7.x86_646/9Verifying:libaio-0.3.109-13.el7.x86_647/9Verifying:1:mariadb-libs-5.5.52-1.el7.x86_648/9Verifying:2:postfix-2.10.1-6.el7.x86_649/9Installed:mysql-community-libs.x86_640:5.7.27-1.el7mysql-community-libs-compat.x86_640:5.7.27-1.el7mysql-community-server.x86_640:5.7.27-1.el7DependencyInstalled:libaio.x86_640:0.3.109-13.el7mysql-community-client.x86_640:5.7.27-1.el7mysql-community-common.x86_640:5.7.27-1.el7DependencyUpdated:postfix.x86_642:2.10.1-7.el7Replaced:mariadb-libs.x86_641:5.5.52-1.el7Complete!

6.启用MySQL

在CentOS 6中，我们一般通过service mysqld start来启动mysql，在CentOS 7中，如果直接输入service mysqld start，则会出现以下信息：

这是因为 CentOS 7 下重启服务不再通过service操作，而是通过systemctl操作，因此我们可以输入命令：

启动mysql：systemctl start mysqld.service
查看mysql状态：systemctl status mysqld.service

7.登录mysql

mysql -u root -p

在要求输入密码时，因为mysql 5.7的初始密码不是空，直接按回车键不能成功登录，因此需先找到初始密码，才能登录。

grep 'temporary password' /var/log/mysqld.log

如上，最后的内容就是初始密码。

再次登录，输入初始密码，即可成功登录。

第一次登录成功后，发现不能执行操作，同时提示让修改密码。

8.修改登录密码

alter user root@localhost identified by '新密码'

这里，我想设置新密码为 123456，但出现了报错，这里的报错是mysql的密码策略问题，输入命令：show variables like 'validate_password%'，查看 mysql 初始的密码策略，发现密码的最小长度为8，密码的验证强度等级为MEDIUM，可以修改一下密码策略：

设置密码的验证强度等级：set global validate_password_policy=LOW
设置密码的最小长度：set global validate_password_length=6

好了，这时我们再次执行修改密码的sql，便不会报错了。

最后通过flush privileges刷新权限，使当前操作立即生效，就大功告成了。

注意：最后这里，也可以不修改密码策略，只要自己设置的密码满足MySQL的原密码策略即可。

mysql 添加远程访问

第一种：mysql 5.0（两种方式）

一、

在命令窗口输入，mysql -u root -p 回车，并输入密码

执行 use mysql

执行下面句子，查看权限，root默认权限为localhost

select user,host from user;

更改root权限为%

update user set host = '%' where user = 'root';

刷新

flush privileges;

二、

在命令窗口输入，mysql -u root -p 回车，并输入密码

执行 use mysql

设置test为账户，密码为：ceshipwd，权限为%，所有人

grant all on *.* to 'test'@'%' identified by 'ceshipwd';

如果权限不设置为所有人，可设定固定访问IP如下：

grant all on *.* to 'test'@'111.111.111.111' identified by 'ceshipwd';

最后，刷新

flush privileges;

第一种：mysql 8.0以上（两种方式）

一、

在命令窗口输入，mysql -u root -p 回车，并输入密码

执行 use mysql

执行下面句子，查看权限，root默认权限为localhost

select user,host from user;

更改root权限为%

update user set host = '%' where user = 'root';

刷新

flush privileges;

二、

在命令窗口输入，mysql -u root -p 回车，并输入密码

执行 use mysql

设置test为账户，密码为：ceshipwd，权限为%，所有人

先建立账号：

create user 'test'@'%' identified with mysql_native_password by 'ceshipwd';

再添加账号权限

grant all on *.* to 'test'@'%';

如果权限不设置为所有人，可设定固定访问IP如下：

grant all on *.* to 'test'@'111.111.111.111';

最后，刷新

flush privileges;

三、

各版本修改密码的格式：

mysql5.0格式如下：

本地可以访问

alter user 'ceshi'@'localhost' identified by 'ceshipw';

所有都可以访问

alter user 'ceshi'@'%' identified by 'ceshipw';

mysql8.0以上格式如下：

本地可以访问

alter user 'ceshi'@'localhost' identifiedwith mysql_native_password by 'ceshipw';

所有都可以访问

alter user 'ceshi'@'%' identified with mysql_native_password by 'ceshipw';

*使用navicat连接mysql8.0数据库时，提示1251-client does not support authentication protocol requested by server;consider upgrading mysql client 解决办法：

进入数据库，更新一下认证格式usermysql;#下面方式是修改密码的格式，即可正常访问alteruser'ceshi'@'%'identifiedwithmysql_native_passwordby'ceshipw';flushprivileges;