本篇文章主要介绍了"帮助别人就是帮助自己 Mysql help命令（帮助信息）中文注解"，主要涉及到帮助别人就是帮助自己方面的内容，对于MySql感兴趣的同学可以参考一下：
在开发或测试环境在碰到mysql相关故障时，大多数朋友可能会通过论坛发帖，QQ群讨论方式来获取帮助。该方式是获取帮助的有效途径之一。然而如果在生产环境，在没有网...
在开发或测试环境在碰到mysql相关故障时，大多数朋友可能会通过论坛发帖，QQ群讨论方式来获取帮助。该方式是获取帮助的有效途径之一。然而如果在生产环境，在没有网络的环境下，这些方式就无助于问题的解决。无论何种数据库，从官方网站获取帮助是最直接最有效的方式。其次没有网络的环境下，我们可以通过MySQL客户端工具自带的帮助信息来解决问题。
1)MySQL官方手册
和Oracle官方文档一下，MySQL官方手册是获取MySQL帮助最直接最效的方式。该手册包含很多个部分，比如有关SQL的语法，MySQL安装方式，MySQL的系统变量，状态变量，命令行的常用工具，数据库的管等等。总之是一个MySQL数据相关的大合集。支持PDF及html方式下载。
下载位置：http://dev.mysql.com/doc/
2)MySQL客户端工具自带的帮助
获取mysql有关的帮助信息，直接在mysql提示符下输入help即可获得有关在mysql客户端相关的帮助信息。
这个方式与Oracle SQL*plus下的help 是类似的。
mysql> help
For information about MySQL products and services, visit:
http://www.mysql.com/
For developer information, including the MySQL Reference Manual, visit:
http://dev.mysql.com/
To buy MySQL Enterprise support, training, or other products, visit:
https://shop.mysql.com/
List of all MySQL commands:
Note that all text commands must be first on line and end with ';'
? (\?) Synonym for `help'.
clear (\c) Clear the current input statement. --清除当前输入的语句
connect (\r) Reconnect to the server. Optional arguments are db and host. --重新连接，通常用于被剔除或异常断开后重新连接，SQL*plus下也有这样一个connect命令
delimiter (\d) Set statement delimiter. --设置命令终止符，缺省为；，比如我们可以设定为/来表示语句结束
edit (\e) Edit command with $EDITOR. --编辑缓冲区的上一条SQL语句到文件，缺省调用vi，文件会放在/tmp路径下
ego (\G) Send command to mysql server, display result vertically. --控制结果显示为垂直显示
exit (\q) Exit mysql. Same as quit. --退出mysql
go (\g) Send command to mysql server. --发送命令到mysql服务
help (\h) Display this help.
nopager (\n) Disable pager, print to stdout. --关闭页设置，打印到标准输出
notee (\t) Don't write into outfile. --关闭输出到文件
pager (\P) Set PAGER [to_pager]. Print the query results via PAGER. --设置pager方式，可以设置为调用more,less等等，主要是用于分页显示
print (\p) Print current command.
prompt (\R) Change your mysql prompt. --改变mysql的提示符
quit (\q) Quit mysql.
rehash (\#) Rebuild completion hash. --自动补齐相关对象名字
source (\.) Execute an SQL script file. Takes a file name as an argument. --执行脚本文件
status (\s) Get status information from the server. --获得状态信息
system (\!) Execute a system shell command. --执行系统命令
tee (\T) Set outfile [to_outfile]. Append everything into given outfile.--操作结果输出到文件
use (\u) Use another database. Takes database name as argument. --切换数据库
charset (\C) Switch to another charset. Might be needed for processing binlog with multi-byte charsets. --设置字符集
warnings (\W) Show warnings after every statement. --打印警告信息
nowarning (\w) Don't show warnings after every statement.
--上面的所有命令，扩号内的为快捷操作，即只需要输入“\”+ 字母即可执行
For server side help, type 'help contents' --注意这里的描述help contents将获得服务器端的相关帮助信息
--演示部分，演示常用命令
--connect命令
mysql> connect chardb localhost;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Connection id: 5
Current database: chardb
--设置分页，在多余一个页面显示时会不停的翻滚，用该命令可以设置分页，设置为调用系统命令
mysql> pager more --设置为more方式
PAGER set to 'more'
mysql> select table_name,table_type,engine from information_schema.tables; --该查询会超出一屏显示后按空格键会自动翻滚到下一屏
mysql> pager tail -5; --设置输出尾部5行
PAGER set to 'tail -5'
mysql> select table_name,table_type,engine from information_schema.tables;
| setup_timers | BASE TABLE | PERFORMANCE_SCHEMA |
| threads | BASE TABLE | PERFORMANCE_SCHEMA |
| animals | BASE TABLE | InnoDB |
| shop | BASE TABLE | InnoDB |
+----------------------------------------------+-------------+--------------------+
92 rows in set (0.02 sec)
mysql> pager; --查看当前的pager设置
PAGER set to 'tail -5'
mysql> nopager; --切换到标准(缺省)pager方式
PAGER set to stdout
--tee命令，输出日志文件
mysql> tee /tmp/query.log --开启输出到文件，相当与SQL*plus下的spool
Logging to file '/tmp/query.log'
mysql> select table_name,table_type,engine from information_schema.tables;
+----------------------------------------------+-------------+--------------------+
| table_name | table_type | engine |
+----------------------------------------------+-------------+--------------------+
| CHARACTER_SETS | SYSTEM VIEW | MEMORY |
| COLLATIONS | SYSTEM VIEW | MEMORY |
.............
mysql> notee; --关闭输出到文件，相当于SQL*Plus下的spool off
Outfile disabled.
mysql> system tail /tmp/query.log --查看输出的日志文件
| setup_consumers | BASE TABLE | PERFORMANCE_SCHEMA |
| setup_instruments | BASE TABLE | PERFORMANCE_SCHEMA |
| setup_timers | BASE TABLE | PERFORMANCE_SCHEMA |
| threads | BASE TABLE | PERFORMANCE_SCHEMA |
| animals | BASE TABLE | InnoDB |
| shop | BASE TABLE | InnoDB |
+----------------------------------------------+-------------+--------------------+
92 rows in set (0.02 sec)
--改变mysql提示符
mysql> prompt SessionA>
PROMPT set to 'SessionA> '
--恢复到缺省提示符
SessionA> prompt;
Returning to default PROMPT of mysql>
--执行sql脚本文件
mysql> system more query.sql --注意，此时为当前目录
use chardb
select * from tb_isam;
mysql> source query.sql
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
+------+-------+
| id | value |
+------+-------+
| 1 | a |
| 2 | b |
| 3 | c |
| 4 | f |
+------+-------+
4 rows in set (0.00 sec)
--获取状态信息
mysql> status;
--------------
mysql Ver 14.14 Distrib 5.5.37, for Linux (x86_64) using readline 5.1
Connection id: 6
Current database: chardb
Current user: root@localhost
SSL: Not in use
Current pager: less
Using outfile: ''
Using delimiter: ;
Server version: 5.5.37-log MySQL Community Server (GPL)
Protocol version: 10
Connection: Localhost via UNIX socket
Server characterset: latin1
Db characterset: utf8
Client characterset: latin1
Conn. characterset: latin1
UNIX socket: /var/lib/mysql/mysql.sock
Uptime: 3 hours 10 min 59 sec
Threads: 1 Questions: 97 Slow queries: 0 Opens: 313 Flush tables: 1 Open tables: 51 Queries per second avg: 0.008
--------------
--修改客户端字符集
mysql> charset gbk;
Charset changed
mysql> \s
--------------
mysql Ver 14.14 Distrib 5.5.37, for Linux (x86_64) using readline 5.1
Connection id: 6
Current database: chardb
Current user: root@localhost
SSL: Not in use
Current pager: less
Using outfile: ''
Using delimiter: ;
Server version: 5.5.37-log MySQL Community Server (GPL)
Protocol version: 10
Connection: Localhost via UNIX socket
Server characterset: latin1
Db characterset: utf8
Client characterset: gbk ---客户端和conn端字符集都变成gbk了。
Conn. characterset: gbk
UNIX socket: /var/lib/mysql/mysql.sock
Uptime: 3 hours 13 min 33 sec
Threads: 1 Questions: 105 Slow queries: 0 Opens: 313 Flush tables: 1 Open tables: 51 Queries per second avg: 0.009
--------------
mysql> warnings;
Show warnings enabled.
mysql> selecs 1;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'selecs 1' at line 1
mysql> show warnings;
+-------+------+------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Level | Code | Message |
+-------+------+------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Error | 1064 | You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'selecs 1' at line 1 |
+-------+------+------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)
mysql> show errors;
+-------+------+------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Level | Code | Message |
+-------+------+------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Error | 1064 | You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'selecs 1' at line 1 |
+-------+------+------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)
mysql> nowarning;
Show warnings disabled.3、服务端的相关帮助
