mysq在命令行模式下执行shell命令

mysql可以在命令行模式下执行shell命令

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.
connect (\r) Reconnect to the server. Optional arguments are db and host.
delimiter (\d) Set statement delimiter.
edit (\e) Edit command with $EDITOR.
ego (\G) Send command to mysql server, display result vertically.
exit (\q) Exit mysql. Same as quit.
go (\g) Send command to mysql server.
help (\h) Display this help.
nopager (\n) Disable pager, print to stdout.
notee (\t) Don't write into outfile.
pager (\P) Set PAGER [to_pager]. Print the query results via PAGER.
print (\p) Print current command.
prompt (\R) Change your mysql prompt.
quit (\q) Quit mysql.
rehash (\#) Rebuild completion hash.
source (\.) Execute an SQL script file. Takes a file name as an argument.
status (\s) Get status information from the server.
system (\!) Execute a system shell command.
tee (\T) Set outfile [to_outfile]. Append everything into given outfile.
use (\u) Use another database. Takes database name as argument.
charset (\C) Switch to another charset. Might be needed for processing binlog with multi-byte charsets.
warnings (\W) Show warnings after every statement.
nowarning (\w) Don't show warnings after every statement.

For server side help, type 'help contents'

mysql> system ls
20171024.txt 20171026.txt derby.log files.txt hello.txt json.scala log1.txt log.txt metastore_db mm.txt name.csv namejson.txt spark-2.2.0-bin-hadoop2.7 tian.txt

mysql> \! ls /var/lib
alternatives  cloud  dhclient  logrotate.status  mlocate      mysql-keyring  ntp       postfix  random-seed  rpm      stateless  yum
authconfig    dbus   games     misc              mysql-files  net-snmp       plymouth  prelink  readahead    rsyslog  udev

---------------------------

mysql> use zqgamedb;
Database changed
mysql> select database();
+------------+
| database() |
+------------+
| zqgamedb   |
+------------+
1 row in set (0.00 sec)

-----------------------

mysql> select user();
+----------------+
| user()         |
+----------------+
| root@localhost |
+----------------+
1 row in set (0.00 sec)

---------------------------

SHOW STATUS   返回服务器状态

-------------

mysql> show processlist;
+------+------+---------------------+----------+---------+-------+----------+------------------+
| Id   | User | Host                | db       | Command | Time  | State    | Info             |
+------+------+---------------------+----------+---------+-------+----------+------------------+
| 1467 | qzls | 10.135.95.201:51967 | mysql    | Sleep   | 13748 |          | NULL             |
| 1471 | qzls | 10.135.95.201:51973 | mysql    | Sleep   | 37468 |          | NULL             |
| 1476 | root | 10.135.95.201:51989 | share    | Sleep   |   876 |          | NULL             |
| 1477 | qzls | 10.135.95.201:51990 | mysql    | Sleep   |   675 |          | NULL             |
| 1522 | qzls | 10.135.95.201:52112 | mysql    | Sleep   |  1064 |          | NULL             |
| 1533 | qzls | 10.135.95.201:52688 | mysql    | Sleep   |  1064 |          | NULL             |
| 1534 | qzls | 10.135.95.201:52781 | mysql    | Sleep   | 13746 |          | NULL             |
| 1552 | root | 10.135.95.201:62999 | share    | Sleep   | 13746 |          | NULL             |
| 1554 | qzls | 10.135.95.201:63559 | mysql    | Sleep   | 32968 |          | NULL             |
| 1567 | root | localhost           | zqgamedb | Sleep   |  7705 |          | NULL             |
| 1568 | root | localhost           | zqgamedb | Query   |     0 | starting | show processlist |
+------+------+---------------------+----------+---------+-------+----------+------------------+

----------------------------

show variables like '%max_connections%'; 查看最大连接数

mysql> show variables like '%max_conn%';
+--------------------+--------+
| Variable_name      | Value  |
+--------------------+--------+
| max_connect_errors | 100000 |
| max_connections    | 2000   |
+--------------------+--------+
2 rows in set (0.00 sec)

----------------------------------------------------------------------

mysql> show status like '%connections%';
+-----------------------------------+---------------------+
| Variable_name                     | Value               |
+-----------------------------------+---------------------+
| Connection_errors_max_connections | 0                   |
| Connections                       | 1569                |
| Max_used_connections              | 74                  |
| Max_used_connections_time         | 2018-07-13 14:22:49 |
+-----------------------------------+---------------------+
4 rows in set (0.00 sec)

Aborted_clients 由于客户没有正确关闭连接已经死掉，已经放弃的连接数量。
Aborted_connects 尝试已经失败的MySQL服务器的连接的次数。
Connections 试图连接MySQL服务器的次数。
Created_tmp_tables 当执行语句时，已经被创造了的隐含临时表的数量。
Delayed_insert_threads 正在使用的延迟插入处理器线程的数量。
Delayed_writes 用INSERT DELAYED写入的行数。
Delayed_errors 用INSERT DELAYED写入的发生某些错误(可能重复键值)的行数。
Flush_commands 执行FLUSH命令的次数。
Handler_delete 请求从一张表中删除行的次数。
Handler_read_first 请求读入表中第一行的次数。
Handler_read_key 请求数字基于键读行。
Handler_read_next 请求读入基于一个键的一行的次数。
Handler_read_rnd 请求读入基于一个固定位置的一行的次数。
Handler_update 请求更新表中一行的次数。
Handler_write 请求向表中插入一行的次数。
Key_blocks_used 用于关键字缓存的块的数量。
Key_read_requests 请求从缓存读入一个键值的次数。
Key_reads 从磁盘物理读入一个键值的次数。
Key_write_requests 请求将一个关键字块写入缓存次数。
Key_writes 将一个键值块物理写入磁盘的次数。
Max_used_connections 同时使用的连接的最大数目。
Not_flushed_key_blocks 在键缓存中已经改变但是还没被清空到磁盘上的键块。
Not_flushed_delayed_rows 在INSERT DELAY队列中等待写入的行的数量。
Open_tables 打开表的数量。
Open_files 打开文件的数量。
Open_streams 打开流的数量(主要用于日志记载）
Opened_tables 已经打开的表的数量。
Questions 发往服务器的查询的数量。
Slow_queries 要花超过long_query_time时间的查询数量。
Threads_connected 当前打开的连接的数量。
Threads_running 不在睡眠的线程数量。
Uptime 服务器工作了多少秒。