Environment variables for MySQL

Environment variables for MySQL

• Server variables: Adjust MySQL's working properties, determined by the MySQL configuration file
• State variables: Self-statistics that are output after MySQL runs

View MySQL's environment variables under Linux

1. Get MySQL client Help

#/usr/local/mysql/bin/mysql–help–v (in the Help message--is the MySQL client command, not--is the MySQL server variable)

Reading order of 2.MySQL configuration files

/etc/my.cnf >/etc/mysql/my.cnf >/usr/local/mysql/etc/my.cnf (Find configuration files in this order)

Note: The end result is a collection of all profiles, the same option is valid at the last read

To view the global variables for MySQL:

To view the environment variables currently connected to MySQL:

User management for MySQL

Tip: View user passwords in MySQL

1. Create a user

GRANT all on * * to ' localhost '; (anonymous user created)

2. Change user password

UPDATE mysql.user SET password= ' where user= ' root ' and host= ' localhost ';

3. Delete a user

Mode one: DELETE from Mysql.user WHERE password= ' and user= ' root ';

Mode two: DROP user @ Host

Wildcard characters for Ps:mysql

%: All Users

_: Any character of a unit length (note a unit length)

Set User settings password
1. Set a password for the user individually
Format:
SET PASSWORD for ' UserName ' @ ' HostName ' = PASSWORD (' Newpss ')
2. Batch modify passwords for multiple users
Format:
UPDATE mysql.user SET password= ' newpass ' WHERE condition
3. Using a MySQL client tool-mysqladmin
Format:
Mysqladmin-u User-P old password Password new password-h host
Note: The host here refers to the user can use this password to log on to the host on the MySQL

MySQL client and server-side communication
1, local communication: MySQL client and server side on the same host, and to be based on the LO interface or 127.0.0.1 communication.
Linux System (Unix sock)
            compile installation:/tmp/ Mysql.sock
            RPM Installation:/var/lib/mmysql/ Mysql.sock
Windows
            memory
             Pipe
2, remote communication: MySQL client and server side on the same host, but the communication is based on IP communication , or the client and server side are not on the same host.
Socket:ip+port
Common clients
    mysql
    mysqladmin
    Common options for Mydqldump
    mysqlcheck       
Client Tools
    -u--user=
   -H--host=
   -P--password=
   - -port=
   --protocol={socket|memory|pipe}
   --socket=

MySQL
    two modes of operation
    1, interactive mode
         MySQL >
    2, Batch mode
        # mysql-u root-p123 < ; 1.sql
   
Commands available in interactive mode
    server-side commands:
         access: Help COMMAND;
    Client commands:
        \h
         \c
        \g
        \g
        \q
        \s
         \!
        \#
Queries the keywords available to MYQL clients:
Help contents;  

MySQL Client-only options
-C or-compress: Compressed transport
--DEFAULT-CHARACTER-SET=NAME Specifies the type of character set used by the MySQL client.
-E,--execute=name: Execute mysql command in bash
-H or--html: output results as Web pages

The MySQL prompt
MySQL >
Line-continuation character
/*> annotation Characters
' >

MySQL operation log
~/.mysql_history

MySQL shortcut keys
Ctrl+w: One word before each deletion of the cursor
Ctrl+u: Delete all before the cursor
Ctrl+y: Pasting
CTRL + A: Cursor moves to the beginning of the line
Ctrl+e: Cursor moves to end of line

Environment variables for MySQL