一、问题描述
     今日上午接到同事的召唤，让帮着给查看一下生产数据Mysql数据库软件版本。呵呵，对于小白的我，当然是先答应后学习喽。并且漂亮的完成任务。

二、实验（非生产环境）
1.登录mysql环境时，有服务版本号，此处为5.6.22
[root@suzzy ~]# mysql
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 39
Server version: 5.6.22-enterprise-commercial-advanced MySQL Enterprise Server - Advanced Edition (Commercial)

Copyright (c) 2000, 2014, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql>

2.使用 mysql -V 来查看版本信息
 [root@suzzy ~]# mysql -V
mysql  Ver 14.14 Distrib 5.6.22, for Linux (x86_64) using  EditLine wrapper

3.使用 mysql --help 来查看版本信息
[root@suzzy ~]# mysql --help |grep Distrib
mysql  Ver 14.14 Distrib 5.6.22, for Linux (x86_64) using  EditLine wrapper
[root@suzzy ~]#

4.进入mysql命令后，使用status命令
mysql> status
--------------
mysql  Ver 14.14 Distrib 5.6.22, for Linux (x86_64) using  EditLine wrapper

Connection id:          51
Current database:
Current user:           root@localhost
SSL:                    Not in use
Current pager:          stdout
Using outfile:          ''
Using delimiter:        ;
Server version:         5.6.22-enterprise-commercial-advanced MySQL Enterprise Server - Advanced Edition (Commercial)
Protocol version:       10
Connection:             Localhost via UNIX socket
Server characterset:    latin1
Db     characterset:    latin1
Client characterset:    utf8
Conn.  characterset:    utf8
UNIX socket:            /var/lib/mysql/mysql.sock
Uptime:                 45 days 23 hours 9 min 46 sec

Threads: 1  Questions: 124  Slow queries: 0  Opens: 48  Flush tables: 1  Open tables: 41  Queries per second avg: 0.000

5.使用系统函数
mysql> select version();
+---------------------------------------+
| version()                             |
+---------------------------------------+
| 5.6.22-enterprise-commercial-advanced |
+---------------------------------------+
1 row in set (0.00 sec)

mysql> select @@version;
+---------------------------------------+
| @@version                             |
+---------------------------------------+
| 5.6.22-enterprise-commercial-advanced |
+---------------------------------------+
1 row in set (0.00 sec)

6.查看变量
mysql> show variables like '%version%';
+-------------------------+---------------------------------------------------------+
| Variable_name           | Value                                                   |
+-------------------------+---------------------------------------------------------+
| innodb_version          | 5.6.22                                                  |
| protocol_version        | 10                                                      |
| slave_type_conversions  |                                                         |
| version                 | 5.6.22-enterprise-commercial-advanced                   |
| version_comment         | MySQL Enterprise Server - Advanced Edition (Commercial) |
| version_compile_machine | x86_64                                                  |
| version_compile_os      | Linux                                                   |
+-------------------------+---------------------------------------------------------+
7 rows in set (0.00 sec)

7.mysqladmin 命令方式
[root@suzzy ~]#  mysqladmin -uroot -p -hlocalhost version;
Enter password:
mysqladmin  Ver 8.42 Distrib 5.6.22, for Linux on x86_64
Copyright (c) 2000, 2014, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Server version          5.6.22-enterprise-commercial-advanced
Protocol version        10
Connection              Localhost via UNIX socket
UNIX socket             /var/lib/mysql/mysql.sock
Uptime:                 46 days 7 min 45 sec

Threads: 1  Questions: 133  Slow queries: 0  Opens: 48  Flush tables: 1  Open tables: 41  Queries per second avg: 0.000

三、官方说明  2.1.1章节
The naming scheme in MySQL 5.6 uses release names that consist of three numbers and a suffix; for example, mysql-5.6.1-m1. The numbers within the release name are interpreted as follows:
The first number (5) is the major version and describes the file format. All MySQL 5 releases have the same file format.
The second number (6) is the release level. Taken together, the major version and release level constitute the release series number.
The third number (1) is the version number within the release series. This is incremented for each new release. Usually you want the latest version for the series you have chosen.

四、总结：
     看似简单的工作，如果没有接触过人还真是不晓得。所以DBA的大小朋友们，把你不会的东西提早学习一下，会受益匪浅的。想起来一句话（书到用时方恨少；事非经过不知难。）译：知识总是在运用时才让人感到太不够了，许多事情如果不亲身经历过就不知道它有多难。