Trivial database HOWTO

MySQL is just one of a number of excellent database
implementations.  MySQL is popular because it's free.
http://www.mysql.com/


Database setup:

Set up password "funker":
	mysqladmin -u root password funker
(You get 'Access denied for user:' if you enter
the wrong password.)

Create a database "testdb":
	mysqladmin -u root -pfunker create testdb

In /var/lib/mysql, /testdb is created.
	ls -al /var/lib/mysql/testdb/



------------ Interactive SQL Queries ------------
Now you can interactively edit the database with
	mysql -u root -pfunker -Dtestdb

Now you type SQL commands.  CREATE builds a new table.

CREATE TABLE log (
	num INT NOT NULL auto_increment,
	importance INT DEFAULT '0' NOT NULL,
	date TIMESTAMP NOT NULL,
	user VARCHAR(10) DEFAULT '',
	item VARCHAR(40),
	PRIMARY KEY (num),
	KEY xdate(date),
	KEY ximportance(importance)
);

SHOW TABLES;
DESCRIBE log;


Using the database:
Once the tables are set up (a one-time step for most projects),
you can then add new records with INSERT:

INSERT INTO log (importance,user,item) 
	VALUES (1,"olawlor",'Created table; start of debugging');
INSERT INTO log (importance,user,item) 
	VALUES (0,"olawlor",'Checking out tables...');
INSERT INTO log (importance,user,item) 
	VALUES (0,"nobody",'Silly crap');
INSERT INTO log (importance,user,item) 
	VALUES (1,"nobody",'Not so silly no more!');


Note that spaces (e.g., between the table name and list of columns)
are important.

You "query" or display the data in the table with SELECT:

SELECT * FROM log;
SELECT * FROM log WHERE importance=1;
SELECT * FROM log WHERE importance>0 AND user="nobody";


You can also modify the table definition--even for a table 
that already has data in it.

ALTER TABLE log ADD ( files VARCHAR(10) default '' );


-------------------- C to Database Interface --------------
http://dev.mysql.com/doc/refman/5.0/en/apis.html

Create a MYSQL object.  Issue SQL queries.  Read results.

See subdirectories of this example program.


------------------- Perl Interface: DBI -----------------
http://search.cpan.org/~timb/DBI/DBI.pm

See "perldoc DBI".

------------------- Java Interface: JBDC -----------------
http://java.sun.com/products/jdbc/

--- Embedding Database Server in Your Program ---
http://dev.mysql.com/doc/refman/5.0/en/libmysqld-example.html