#### Mysql安装
- 卸载Centos7自带的mariadb
- 安装mysql
```shell
mkdir /export/software/mysql
#上传mysql-5.7.29-1.el7.x86_.rpm-bundle.tar 到上述文件夹下 解压
tar xvf mysql-5.7.29-1.el7.x86_.rpm-bundle.tar
#执行安装
yum -y install libaio
[root@node3 mysql]# rpm -ivh mysql-community-common-5.7.29-1.el7.x86_.rpm mysql-community-libs-5.7.29-1.el7.x86_.rpm mysql-community-client-5.7.29-1.el7.x86_.rpm mysql-community-server-5.7.29-1.el7.x86_.rpm
warning: mysql-community-common-5.7.29-1.el7.x86_.rpm: Header V3 DSA/SHA1 Signature, key ID 5072e1f5: NOKEY
Preparing... ################################# [100%]
Updating / installing...
1:mysql-community-common-5.7.29-1.e################################# [ 25%]
2:mysql-community-libs-5.7.29-1.el7################################# [ 50%]
3:mysql-community-client-5.7.29-1.e################################# [ 75%]
4:mysql-community-server-5.7.29-1.e################ ( 49%)
```
- mysql初始化设置
```shell
#初始化
mysqld --initialize
#更改所属组
chown mysql:mysql /var/lib/mysql -R
#启动mysql
systemctl start mysqld.service
#查看生成的临时root密码
cat /var/log/mysqld.log
[Note] A temporary password is generated for root@localhost: o+TU+KDOm004
```
- 修改root密码 授权远程访问 设置开机自启动
```shell
[root@node2 ~]# mysql -u root -p
Enter password: #这里输入在日志中生成的临时密码
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 3
Server version: 5.7.29
Copyright (c) 2000, 2020, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql>
#更新root密码 设置为hadoop
mysql> alter user user() identified by "hadoop";
Query OK, 0 rows affected (0.00 sec)
#授权
mysql> use mysql;
mysql> GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY 'hadoop' WITH GRANT OPTION;
mysql> FLUSH PRIVILEGES;
#mysql的启动和关闭 状态查看 （这几个命令必须记住）
systemctl stop mysqld
systemctl status mysqld
systemctl start mysqld
#建议设置为开机自启动服务
[root@node2 ~]# systemctl enable mysqld
Created symlink from /etc/systemd/system/multi-user.target.wants/mysqld.service to /usr/lib/systemd/system/mysqld.service.
#查看是否已经设置自启动成功
[root@node2 ~]# systemctl list-unit-files | grep mysqld
mysqld.service enabled
```
- Centos7 ==干净==卸载mysql 5.7
