Difference between revisions of "MySQL"

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select * from mysql.user;
 
select * from mysql.user;
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==Special Characters Names Users Databases Problems==
 +
These Characters can run you into problems cause Signs like Quotes (` ´ ) are NOT DISPLAYED at the mysql Console!
 +
<pre>
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Character  Escape Sequence
 +
\0  An ASCII NUL (0x00) character.
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\'  A single quote (“'”) character.
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\"  A double quote (“"”) character.
 +
\b  A backspace character.
 +
\n  A newline (linefeed) character.
 +
\r  A carriage return character.
 +
\t  A tab character.
 +
\Z  ASCII 26 (Control-Z). See note following the table.
 +
\\  A backslash (“\”) character.
 +
\%  A “%” character. See note following the table.
 +
\_  A “_” character. See note following the table.
 
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Revision as of 01:21, 17 May 2017

MySQL commands for the MySQL console

Always use mysql "console" instead of "phpmyadmin" for Security reasons!!!

If you want to show the size of all databases installed do:

login as mysql admin

mysql -u admin -p

at the mysql prompt do:

mysql> SELECT table_schema "Data Base Name", sum( data_length + index_length) / 1024 / 1024 
"Data Base Size in MB" FROM information_schema.TABLES GROUP BY table_schema;

Create database named "test":

mysql> create database test; 

Delete database named "test":

mysql> drop database test;

Update/Reload Databases at MYSQL Server:

mysql> flush privileges;

Dump all Databases - Note: This do only if you want Restore the same Server, cause MySQL System Databases like "mysql or information_schema" are dumped too!! This will break on other Servers!

mysql > mysqldump -u root -p --opt --all-databases > databases-dump-$date.sql

mysql > Its better you write a Bash Script to dump every Database for its own! This does not scramble a fresh setup!

User Handling

CREATE USER 'newuser'@'localhost' IDENTIFIED BY 'password';

GRANT ALL PRIVILEGES ON db.* TO ‘user’@'localhost’;

UPDATE mysql.user SET Password=PASSWORD('newpassword') WHERE User='username'; FLUSH PRIVILEGES;

List Users

Login to MySQL Console as Admin, go into the System Database called mysql, and list.

mysql -u mysqladminname -p

use mysql;

select * from mysql.user;

Special Characters Names Users Databases Problems

These Characters can run you into problems cause Signs like Quotes (` ´ ) are NOT DISPLAYED at the mysql Console!

Character   Escape Sequence
\0  An ASCII NUL (0x00) character.
\'  A single quote (“'”) character.
\"  A double quote (“"”) character.
\b  A backspace character.
\n  A newline (linefeed) character.
\r  A carriage return character.
\t  A tab character.
\Z  ASCII 26 (Control-Z). See note following the table.
\\  A backslash (“\”) character.
\%  A “%” character. See note following the table.
\_  A “_” character. See note following the table.