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

版本	用户中的%是否包括localhost
mysql8.0	包括
mysql5.7	包括
mysql5.6	不包括
mysql5.1	不包括
mariadb 10.3	不包括

好了，这篇文章就介绍到了，希望大家以后多多支持。