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这篇文章主要介绍“如何理解 MySQL 用户中的百分号 % 是否包含 localhost”，在日常操作中，相信很多人在如何理解 MySQL 用户中的百分号 % 是否包含 localhost 问题上存在疑惑，丸趣 TV 小编查阅了各式资料，整理出简单好用的操作方法，希望对大家解答”如何理解 MySQL 用户中的百分号 % 是否包含 localhost”的疑惑有所帮助！接下来，请跟着丸趣 TV 小编一起来学习吧！
1 前言
操作 MySQL 的时候发现，有时只建了 % 的账号，可以通过 localhost 连接，有时候却不可以，网上搜索也找不到满意的答案，干脆手动测试一波
2 两种连接方法
这里说的两种连接方法指是执行 mysql 命令时，- h 参数填的是 localhost 还是 IP, 两种连接方式的区别如下
-h 参数为 localhost
当 - h 参数为 localhost 的时候，实际上是使用 socket 连接的（默认连接方式）, 实例如下
[mysql@mysql-test-83 ~]$ /usr/local/mysql57/bin/mysql -utest_user -p -hlocalhost
Enter password:
========= 省略 ===========
mysql status
/usr/local/mysql57/bin/mysql Ver 14.14 Distrib 5.7.21, for linux-glibc2.12 (x86_64) using EditLine wrapper
Connection id: 9
Current database:
Current user: test_user@localhost
SSL: Not in use
Current pager: stdout
Using outfile:
Using delimiter: ;
Server version: 5.7.21-log MySQL Community Server (GPL)
Protocol version: 10
Connection: Localhost via UNIX socket从 Current user 可以看到用户是 xx@localhost, 连接方式为 Localhost via UNIX socket
-h 参数为 IP
当 - h 参数为 IP 的时候，实际上是使用 TCP 连接的, 实例如下
[mysql@mysql-test-83 ~]$ /usr/local/mysql57/bin/mysql -utest_user -p -h227.0.0.1
Enter password:
========= 省略 ===========
mysql status
--------------
/usr/local/mysql57/bin/mysql Ver 14.14 Distrib 5.7.21, for linux-glibc2.12 (x86_64) using EditLine wrapper
Connection id: 11
Current database:
Current user: test_user@127.0.0.1
SSL: Cipher in use is DHE-RSA-AES256-SHA
Current pager: stdout
Using outfile:
Using delimiter: ;
Server version: 5.7.21-log MySQL Community Server (GPL)
Protocol version: 10
Connection: 127.0.0.1 via TCP/IP
Server characterset: utf8从 Current user 可以看到用户是 xx@127.0.0.1, 连接方式为 TCP/IP
3 不同版本的差别
测试方法就是看能不能连接，如果不想看测试过程可以拉到最后看结论
3.1 MySQL 8.0 创建用户
mysql select version();
+-----------+
| version() |
+-----------+
| 8.0.11 |
+-----------+
1 row in set (0.00 sec)
mysql create user test_user@ % identified by test_user
Query OK, 0 rows affected (0.07 sec)使用 localhost 登录
[root@mysql-test-72 ~]# /usr/local/mysql80/bin/mysql -utest_user -p -hlocalhost
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 9
Server version: 8.0.11 MySQL Community Server - GPL
========= 省略 ===========
mysql status
--------------
/usr/local/mysql80/bin/mysql Ver 8.0.11 for linux-glibc2.12 on x86_64 (MySQL Community Server - GPL)
Connection id: 9
Current database:
Current user: test_user@localhost
SSL: Not in use
Current pager: stdout
Using outfile:
Using delimiter: ;
Server version: 8.0.11 MySQL Community Server - GPL
Protocol version: 10
Connection: Localhost via UNIX socket
...使用 IP 登录
[root@mysql-test-72 ~]# /usr/local/mysql80/bin/mysql -utest_user -p -h227.0.0.1
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 8
Server version: 8.0.11 MySQL Community Server - GPL
========= 省略 ===========
mysql status
--------------
/usr/local/mysql80/bin/mysql Ver 8.0.11 for linux-glibc2.12 on x86_64 (MySQL Community Server - GPL)
Connection id: 8
Current database:
Current user: test_user@127.0.0.1
SSL: Cipher in use is DHE-RSA-AES128-GCM-SHA256
Current pager: stdout
Using outfile:
Using delimiter: ;
Server version: 8.0.11 MySQL Community Server - GPL
Protocol version: 10
Connection: 127.0.0.1 via TCP/IP结果显示 8.0 版本的 MySQL, % 包括 localhost
3.2 MySQL 5.7 创建 % 用户
db83-3306 create user test_user@ % identified by test_user
Query OK, 0 rows affected (0.00 sec)使用 localhost 登录
[mysql@mysql-test-83 ~]$ /usr/local/mysql57/bin/mysql -utest_user -p -hlocalhost
========= 省略 ===========
mysql status
/usr/local/mysql57/bin/mysql Ver 14.14 Distrib 5.7.21, for linux-glibc2.12 (x86_64) using EditLine wrapper
Connection id: 9
Current database:
Current user: test_user@localhost
SSL: Not in use
Current pager: stdout
Using outfile:
Using delimiter: ;
Server version: 5.7.21-log MySQL Community Server (GPL)
Protocol version: 10
Connection: Localhost via UNIX socket
....使用 IP 登录
[mysql@mysql-test-83 ~]$ /usr/local/mysql57/bin/mysql -utest_user -p -h227.0.0.1
Enter password:
========= 省略 ===========
mysql status
--------------
/usr/local/mysql57/bin/mysql Ver 14.14 Distrib 5.7.21, for linux-glibc2.12 (x86_64) using EditLine wrapper
Connection id: 11
Current database:
Current user: test_user@127.0.0.1
SSL: Cipher in use is DHE-RSA-AES256-SHA
Current pager: stdout
Using outfile:
Using delimiter: ;
Server version: 5.7.21-log MySQL Community Server (GPL)
Protocol version: 10
Connection: 127.0.0.1 via TCP/IP
Server characterset: utf8
...结果显示 5.7 版本的 MySQL, % 包括 localhost
3.3 MySQL 5.6 创建用户
db83-3306 select version();
+------------+
| version() |
+------------+
| 5.6.10-log |
+------------+
1 row in set (0.00 sec)
db83-3306 create user test_user@ % identified by test_user
Query OK, 0 rows affected (0.00 sec)
使用 localhost 登录
[mysql@mysql-test-83 ~]$ /usr/local/mysql57/bin/mysql -utest_user -p -hlocalhost
Enter password:
ERROR 1045 (28000): Access denied for user test_user @ localhost (using password: YES)使用 IP 登录
[mysql@mysql-test-83 ~]$ /usr/local/mysql57/bin/mysql -utest_user -p -h227.0.0.1
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 3
Server version: 5.6.10-log MySQL Community Server (GPL)
========= 省略 ===========
mysql status
--------------
/usr/local/mysql57/bin/mysql Ver 14.14 Distrib 5.7.21, for linux-glibc2.12 (x86_64) using EditLine wrapper
Connection id: 3
Current database:
Current user: test_user@127.0.0.1
SSL: Not in use
Current pager: stdout
Using outfile:
Using delimiter: ;
Server version: 5.6.10-log MySQL Community Server (GPL)
Protocol version: 10
Connection: 127.0.0.1 via TCP/IP
......
--------------结果显示 MySQL 5.6 的 % 不包括 localhost
3.4 MySQL 5.1 创建用户
mysql select version();
+-----------+
| version() |
+-----------+
| 5.1.73 |
+-----------+
1 row in set (0.00 sec)
mysql create user test_user@ % identified by test_user
Query OK, 0 rows affected (0.00 sec)使用 localhost 登录
[root@chengqm ~]# mysql -utest_user -p
Enter password:
ERROR 1045 (28000): Access denied for user test_user @ localhost (using password: YES)使用 IP 登录
[root@chengqm ~]# mysql -utest_user -p -h227.0.0.1
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 4901339
Server version: 5.1.73 Source distribution
========= 省略 ===========
mysql status
--------------
mysql Ver 14.14 Distrib 5.1.73, for redhat-linux-gnu (x86_64) using readline 5.1
Connection id: 4901339
Current database:
Current user: test_user@127.0.0.1
SSL: Not in use
Current pager: stdout
Using outfile:
Using delimiter: ;
Server version: 5.1.73 Source distribution
Protocol version: 10
Connection: 127.0.0.1 via TCP/IP结果显示 5.1 版本的 % 不包括 localhost
3.5 MariaDB 10.3 创建用户
db83-3306 select version();
+---------------------+
| version() |
+---------------------+
| 10.3.11-MariaDB-log |
+---------------------+
1 row in set (0.000 sec)
db83-3306 create user test_user@ % identified by test_user
Query OK, 0 rows affected (0.001 sec)使用 localhost 登录
[mysql@mysql-test-83 ~]$ /usr/local/mariadb/bin/mysql -utest_user -p -hlocalhost
Enter password:
ERROR 1045 (28000): Access denied for user test_user @ localhost (using password: YES)使用 IP 登录
[mysql@mysql-test-83 ~]$ /usr/local/mariadb/bin/mysql -utest_user -p -h227.0.0.1
Enter password:
Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MariaDB connection id is 12
Server version: 10.3.11-MariaDB-log MariaDB Server
========= 省略 ===========
MariaDB [(none)] status
--------------
/usr/local/mariadb/bin/mysql Ver 15.1 Distrib 10.3.11-MariaDB, for Linux (x86_64) using readline 5.1
Connection id: 12
Current database:
Current user: test_user@127.0.0.1
SSL: Not in use
Current pager: stdout
Using outfile:
Using delimiter: ;
Server: MariaDB
Server version: 10.3.11-MariaDB-log MariaDB Server
Protocol version: 10
Connection: 127.0.0.1 via TCP/IP结果显示 MariaDB 10.3 的 % 不包括 localhost
4 结论版本用户中的 % 是否包括 localhostMySQL8.0 包括 MySQL5.7 包括 MySQL5.6 不包括 MySQL5.1 不包括 MariaDB 10.3 不包括
到此，关于“如何理解 MySQL 用户中的百分号 % 是否包含 localhost”的学习就结束了，希望能够解决大家的疑惑。理论与实践的搭配能更好的帮助大家学习，快去试试吧！若想继续学习更多相关知识，请继续关注丸趣 TV 网站，丸趣 TV 小编会继续努力为大家带来更多实用的文章！
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