數據庫允許遠程登錄
連接數據庫
[root@localhost ~]# mysql -uroot -p
Enter password:
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (111)
數據庫未啟用，啟用數據庫
[root@localhost ~]# ss -tunlp
Netid State Recv-Q Send-Q Local Address:Port Peer Address:Port
udp UNCONN 0 0 192.168.208.246%eth0:68 0.0.0.0:* users:(("NetworkManager",pid=947,fd=20))
udp UNCONN 0 0 127.0.0.1:323 0.0.0.0:* users:(("chronyd",pid=916,fd=6))
udp UNCONN 0 0 [::1]:323 [::]:* users:(("chronyd",pid=916,fd=7))
tcp LISTEN 0 128 127.0.0.1:45233 0.0.0.0:* users:(("node",pid=1900,fd=18))
tcp LISTEN 0 128 0.0.0.0:22 0.0.0.0:* users:(("sshd",pid=956,fd=5))
tcp LISTEN 0 128 [::]:22 [::]:* users:(("sshd",pid=956,fd=7))
3306端口不存在，可以啟用
[root@localhost ~]# systemctl start mariadb.service
[root@localhost ~]# ss -tunlp
Netid State Recv-Q Send-Q Local Address:Port Peer Address:Port
udp UNCONN 0 0 192.168.208.246%eth0:68 0.0.0.0:* users:(("NetworkManager",pid=947,fd=20))
udp UNCONN 0 0 127.0.0.1:323 0.0.0.0:* users:(("chronyd",pid=916,fd=6))
udp UNCONN 0 0 [::1]:323 [::]:* users:(("chronyd",pid=916,fd=7))
tcp LISTEN 0 128 127.0.0.1:45233 0.0.0.0:* users:(("node",pid=1900,fd=18))
tcp LISTEN 0 128 0.0.0.0:22 0.0.0.0:* users:(("sshd",pid=956,fd=5))
tcp LISTEN 0 128 [::]:22 [::]:* users:(("sshd",pid=956,fd=7))
tcp LISTEN 0 80 *:3306 *:* users:(("mysqld",pid=3512,fd=20))
數據庫啟用成功，連接數據庫
[root@localhost ~]# mysql -uroot -p
Enter password:
Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MariaDB connection id is 8
Server version: 10.3.17-MariaDB MariaDB Server
Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
MariaDB [(none)]>
連接成功
設置允許遠程連接
MariaDB [(none)]> show databases;
查看庫
MariaDB [(none)]> use mysql;
切換數據庫，使用另一個數據庫。 將數據庫名稱作為參數。
MariaDB [mysql]> show tables;
查看表
MariaDB [mysql]> select host,user,password from user;
+-----------+------+-------------------------------------------+
| host | user | password |
+-----------+------+-------------------------------------------+
| localhost | root | *81F5E21E35407D884A6CD4A731AEBFB6AF209E1B |
| 127.0.0.1 | root | *81F5E21E35407D884A6CD4A731AEBFB6AF209E1B |
| ::1 | root | *81F5E21E35407D884A6CD4A731AEBFB6AF209E1B |
| % | root | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 |
| % | gogs | *461C3A96BAEF66E327658B3AFF86F8D71BEE3F99 |
+-----------+------+-------------------------------------------+
5 rows in set (0.000 sec)
查看user表的三個字段，% 允許所有地址對應的密碼忘記，刪除所有允許所有地址登錄
MariaDB [mysql]> delete from user where host='%';
Query OK, 2 rows affected (0.000 sec)
MariaDB [mysql]> select host,user,password from user;
+-----------+------+-------------------------------------------+
| host | user | password |
+-----------+------+-------------------------------------------+
| localhost | root | *81F5E21E35407D884A6CD4A731AEBFB6AF209E1B |
| 127.0.0.1 | root | *81F5E21E35407D884A6CD4A731AEBFB6AF209E1B |
| ::1 | root | *81F5E21E35407D884A6CD4A731AEBFB6AF209E1B |
+-----------+------+-------------------------------------------+
3 rows in set (0.000 sec)
刪除成功
MariaDB [mysql]> GRANT ALL PRIVILEGES ON *.* TO 'root'@'%'IDENTIFIED BY 'root' WITH GRANT OPTION;
Query OK, 0 rows affected (0.000 sec)
MariaDB [mysql]> select host,user,password from user;
+-----------+------+-------------------------------------------+
| host | user | password |
+-----------+------+-------------------------------------------+
| localhost | root | *81F5E21E35407D884A6CD4A731AEBFB6AF209E1B |
| 127.0.0.1 | root | *81F5E21E35407D884A6CD4A731AEBFB6AF209E1B |
| ::1 | root | *81F5E21E35407D884A6CD4A731AEBFB6AF209E1B |
| % | root | *81F5E21E35407D884A6CD4A731AEBFB6AF209E1B |
+-----------+------+-------------------------------------------+
4 rows in set (0.000 sec)
MariaDB [mysql]> FLUSH PRIVILEGES;
Query OK, 0 rows affected (0.000 sec)
all privileges：表示將所有權限授予給用戶。也可指定具體的權限，如：SELECT、CREATE、DROP等。
on：表示這些權限對哪些數據庫和表生效，格式：數據庫名.表名，這里寫“*”表示所有數據庫，所有表。如果我要指定將權限應用到test庫的user表中，可以這么寫：test.user
to：將權限授予哪個用戶。格式：”用戶名”@”登錄IP或域名”。%表示沒有限制，在任何主機都可以登錄。比如：”yangxin”@”192.168.0.%”，表示yangxin這個用戶只能在192.168.0IP段登錄
identified by：指定用戶的登錄密碼
with grant option：表示允許用戶將自己的權限授權給其它用戶
FLUSH PRIVILEGES: 更新表
關閉防火牆，防火牆會攔截 mariadb客戶端連接3306端口
systemctl stop firewalld
vs code連接數據庫
安裝插件
- MySQL syntax
- MySQL語法高亮顯示支持
- mysql
- MySQL管理工具
插件安裝成功后進行數據庫連接
按順序輸入完主機名、用戶名、密碼、端口號，最后一項省略 之后左側連接成功