環境資訊：

OS：Ubuntu18.04
MySQL: 5.7.22

安裝MYSQL

在Ubuntu中，預設情況下，只有最新版本的MySQL包含在APT軟體包儲存庫中,要安裝它，只需更新伺服器上的包索引並安裝預設包apt-get。

#命令1
sudo apt-get update
#命令2
sudo apt-get install mysql-server

初始化配置

sudo mysql_secure_installation

　　具體配置項如下：

#1
VALIDATE PASSWORD PLUGIN can be used to test passwords...
Press y
 
|Y for Yes, any other key for No: N (我的選項)

#2
Please set the password for root here...
New password: (輸入密碼)
Re-enter new password: (重複輸入)

#3
By default, a MySQL installation has an anonymous user,
allowing anyone to log into MySQL without having to have
a user account created for them...
Remove anonymous users
 
? (Press y|Y for Yes, any other key for No) : N (我的選項)

#4
Normally, root should only be allowed to connect from
'localhost'. This ensures that someone cannot guess at
the root password from the network...
Disallow root login remotely? (Press y|Y for Yes, any other key for No) : Y (我的選項)

#5
By default, MySQL comes with a database named 
 
'test' that
anyone can access...
Remove test database and access to it? (Press y|Y for Yes, any other key for No) : N (我的選項)

#6
Reloading the privilege tables will ensure that all changes
made so far will take effect immediately.
Reload privilege tables now? (Press y|Y for Yes, any other key for No) : Y (我的選項)

檢查mysql服務狀態

systemctl status mysql.service

配置遠端訪問

在Ubuntu下MySQL預設是隻允許本地訪問的，使用客戶端連線工具是連不上的；
如果你要其他機器也能夠訪問的話，需要進行配置；

步驟如下：

sudo mysql -uroot -proot

grant all privileges on *.* to root@'%' identified by 'root';
flush privileges;

使用客戶端工具嘗試連線，如果連不上：

檢視3306埠是否開啟：

netstat -an|grep 3306

由此可見，3306埠只是在IP 127.0.0.1上監聽，所以拒絕了其他IP的訪問。

解決方法：

sudo vim /etc/mysql/mysql.conf.d/mysqld.cnf 

把其中的bind-address= 127.0.0.1直接註釋掉。

重啟mysql服務

sudo service mysql restart

客戶端連線測試成功。