MySQL新建用户 %到底包不包括localhost?

正常解释

%代表任何客户机都可以连接 localhost代表只可以本机连接

一般情况能访问本地数据库的都是加了权限了，一般都是禁止别的机器访问本地的mysql端口的，如果允许也是要加上指定ip才可以访问，这样才能保证数据库不会被远程访问。

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 -h127.0.0.1 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 -h127.0.0.1 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 -h127.0.0.1 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 -h127.0.0.1 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 -h127.0.0.1 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 -h127.0.0.1 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