服务器安装mysql

1、卸载mysql

1.查看是否安装mysql

首先检查是否已经安装，如果已经安装先删除以前版本，以免安装不成功

[root@localhost ~]# php -v
或
[root@localhost ~]# rpm -qa | grep mysql
或
[root@localhost ~]# yum list installed | grep mysql

如果显示以下内容说明没有安装服务 -bash: gerp: command not found

如果有会显示如下：

mysql57-community-release-el7-8.noarch
mysql-community-common-5.1.73-1.el7.x86_64
mysql-community-client-5.1.73-1.el7.x86_64
mysql-community-server-5.1.73-1.el7.x86_64
mysql-community-libs-5.1.73-1.el7.x86_64
mysql-community-libs-compat-5.1.73-1.el7.x86_64

这时就需要卸载这些安装服务

[root@localhost ~]# rpm -e mysql57-community-release-el7-8.noarch
[root@localhost ~]# rpm -e mysql-community-common-5.1.73-1.el7.x86_64
[root@localhost ~]# rpm -e mysql-community-client-5.1.73-1.el7.x86_64
[root@localhost ~]# rpm -e mysql-community-server-5.1.73-1.el7.x86_64
[root@localhost ~]# rpm -e mmysql-community-libs-5.1.73-1.el7.x86_64
[root@localhost ~]# rpm -e mysql-community-libs-compat-5.1.73-1.el7.x86_64

2.删除配置的mysql空间

• 先查看my.cnf中配置的datadir，不要删错了文件(默认为:/var/lib/mysql)

• 删除datadir

• rm -rf /var/lib/mysql/

• 删除配置

• rm /etc/my.cnf

3.检查剩余的mysql信息

whereis mysql

• 比如像我的就还有如下信息

• mysql: /usr/bin/mysql /usr/lib64/mysql /usr/share/mysql /usr/share/man/man1/mysql.1.gz

• 将搜索出的mysql全都删掉

• 查看mysql依赖

• systemctl list-dependencies mysqld

如果显示只有

mysqld.service

这时就删干净了！ 如果显示像这样，还得继续删

mysqld.service
● ├─system.slice
● └─basic.target
●   ├─microcode.service
●   ├─rhel-dmesg.service
●   ├─selinux-policy-migrate-local-changes@targeted.service
●   ├─paths.target
●   ├─slices.target
●   │ ├─-.slice
●   │ └─system.slice
●   ├─sockets.target
●   │ ├─dbus.socket
●   │ ├─systemd-initctl.socket
●   │ ├─systemd-journald.socket
●   │ ├─systemd-shutdownd.socket
●   │ ├─systemd-udevd-control.socket
●   │ └─systemd-udevd-kernel.socket
●   ├─sysinit.target
●   │ ├─dev-hugepages.mount
●   │ ├─dev-mqueue.mount
●   │ ├─kmod-static-nodes.service
●   │ ├─plymouth-read-write.service
●   │ ├─plymouth-start.service
●   │ ├─proc-sys-fs-binfmt_misc.automount
●   │ ├─rhel-autorelabel-mark.service
●   │ ├─rhel-autorelabel.service
●   │ ├─rhel-domainname.service
●   │ ├─rhel-import-state.service
●   │ ├─rhel-loadmodules.service
●   │ ├─sys-fs-fuse-connections.mount
●   │ ├─sys-kernel-config.mount
●   │ ├─sys-kernel-debug.mount

4.mysql卸载完成

完成上面步骤，终于卸载完成！

2、安装Mysql

1.确保服务器系统处于最新状态

[root@localhost ~]# yum -y update

如果显示内容中含有

[root@localhost ~]# Complete!

说明更新完成

2.重启服务器（可选）

[root@localhost ~]# reboot

3.下载MySql安装包

root@localhost ~]# rpm -ivh http://dev.mysql.com/get/mysql57-community-release-el7-8.noarch.rpm
或
[root@localhost ~]# rpm -ivh http://dev.mysql.com/get/mysql-community-release-el7-5.noarch.rpm

4.安装MySql

[root@localhost ~]# yum install -y mysql-server
或
[root@localhost ~]# yum install mysql-community-server

如果显示以下内容说明安装成功

Complete!

5.修改mysql默认字符集

这里我们需要设置成utf8，打开my.cnf配置文件

vi /etc/my.cnf

添加以下内容：

//在[mysqld]的下面添加服务端字符集
[mysqld]
character-set-server=utf8
collation-server=utf8_general_ci
//lower_case_table_names默认为0,对表名大小写敏感;1不敏感
lower_case_table_names=1
​
//需要在最下方填写客户端字符集
[client]
default-character-set=utf8

6.设置开机启动Mysql

[root@localhost ~]# systemctl enable mysqld.service

检查是否开机自动启动设置成功

[root@localhost ~]# systemctl list-unit-files | grep mysqld

如果显示以下内容说明已经完成自动启动安装

mysqld.service enabled

7.设置开启服务

[root@localhost ~]# systemctl start mysqld.service
或
[root@localhost ~]# service mysqld start

这里需要在实例安全组配置规则，打开3306端口

8.修改mysql登录密码

设置mysql密码，只要满足六位的长度。

alter user 'root'@'localhost' identified by '123456'; 

9.授予远程连接权限(Navicat)

mysql> use mysql
​
mysql> select Host,User from user;
+-----------+------------------+
| Host      | User             |
+-----------+------------------+
| localhost | root             |
| localhost | mysql.infoschema |
| localhost | mysql.session    |
| localhost | mysql.sys        |
+-----------+------------------+
4 rows in set (0.00 sec)
​
mysql> update user set host='%' where user = 'root';
Query OK, 1 row affected (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 0
​
mysql> select Host,User from user;
+-----------+------------------+
| Host      | User             |
+-----------+------------------+
| %         | root             |
| localhost | mysql.infoschema |
| localhost | mysql.session    |
| localhost | mysql.sys        |
+-----------+------------------+
4 rows in set (0.00 sec)
​
mysql> flush privileges;
Query OK, 0 rows affected (0.22 sec)