MySQL新建用户中的%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

好了，这篇文章就介绍到了，希望大家以后多多支持共生网络。