MySQL client tool - mysql

MySQL client tool mysql is a very powerful tool for DBA

1. how to connect to the database 

   mysql -- the CLI command for DBA
--user, -u
--host, -h
--password, -p
--port
--protocol
--database DATABASE, -D
-A disable completion of table and column names

   mysql < SQLfile.sql - execute the SQL batch

2. common commands:

here is the official help document about the mysql client command. these commands will take effect on the client only.

• 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.

I think the most important commands are:
use : switch between database;
MySQL>use mysql
Database changed

status: show briefly about the server performance
MySQL>MySQL>status
--------------
mysql  Ver 14.14 Distrib 5.6.15, for Linux (x86_64) using  EditLine wrapper

Connection id:          3
Current database:       mysql
Current user:           root@localhost
SSL:                    Not in use
Current pager:          stdout
Using outfile:          ''
Using delimiter:        ;
Server version:         5.6.15 MySQL Community Server (GPL)
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:                 14 min 31 sec

Threads: 1  Questions: 60  Slow queries: 0  Opens: 87  Flush tables: 1  Open tables: 80  Queries per second avg: 0.068


source: execute the SQL in batch
system: execute the shell
MySQL>system cat /var/tmp/test.sql
select user,host from user;
MySQL>source /var/tmp/test.sql
+------+-----------+
| user | host      |
+------+-----------+
| root | 127.0.0.1 |
| root | ::1       |
| root | localhost |
| root | x002      |
+------+-----------+
4 rows in set (0.00 sec)

3. how to understand the prompt:

    mysql> --- standard prompt
-> --- waiting for statement delimiter
'> --- waiting for end of '
"> --- waiting for end of "
`> --- waiting for end of `