MySQL - Cheat Sheet

MySQL is a small, fast and highly configurable DBMS. It supports a number of different table fileformats, depending on the requirements of the user.

These are the main MySQL clients and processes (mysqld):

• mysqld - MySQL server daemon
• safe_mysqld - Server process monitor
• mysqlaccess - Tool for creating MySQL users
• mysqladmin - Utility for administering MySQL
• mysqldump - Tool for dumping the contents of a MySQL database. Useful for backing up a database from within the console.
  
• mysql - Command line interface to MySQL
• mysqlshow - List all MySQL database
• Mysql Administrator - This is a GUI tool which makes administering mysql database a painless task. Read more about it here.
  

Field Types in SQL

INTEGER - A whole number
VARCHAR(10) - Up to 10 characters.
CHAR(10) - Fixed number of characters
DATE - A date
DATETIME - Date and time
FLOAT - Floating point numbers

Field Types specific to MySQL

TEXT - Allows up to 65535 characters
DECIMAL(10,2) - Up to 10 digits before the point, 2 after.

Create a database

$ mysqladmin --user=ravi --password=xxx create database addressdb

Using the database

$ mysql --user=ravi --password=xxx
mysql> USE addressdb

Create a table

mysql> CREATE TABLE p_addr (i INTEGER PRIMARY KEY,address TEXT,email VARCHAR(30),pincode DECIMAL(10),phone DECIMAL(15),website TEXT);

Add a column called "name" to the table

mysql> ALTER TABLE p_addr ADD name VARCHAR(30);

Inserting values into table

mysql> INSERT INTO p_addr VALUES (1,"My, present, address","ravi@localhost",681024,2122536, "http://linuxhelp.blogspot.com","Ravi");

List the contents of the table

mysql> SELECT * FROM p_addr;

Delete a row from the table

mysql> DELETE FROM p_addr WHERE i=1;

Rename a column in the table from "address" to "home_address"

mysql> ALTER TABLE p_addr CHANGE address home_address INTEGER;

Note: You cannot use this method to rename a column which is a primary key.

Change an existing record in the table

mysql> UPDATE p_addr SET name="Sumitra" WHERE i=2;

Delete the table from the database

mysql> DROP TABLE p_addr;

List the databases

$ mysqlshow --user=ravi --password=xxx
+-----------+
| Databases |
+-----------+
| addressdb |
| myblog    |
| mysql     |
| test      |
+-----------+

List the tables in the database "addressdb"

$ mysqlshow --user=ravi --password=xxx addressdb

Database: addressdb
+---------+
| Tables  |
+---------+
| p_addr  |
| mytble  |
| phonebk |
+---------+

These are only a subset of the commands in mysql. But this will be enough for creating and maintaining a simple database.