File: sept4.txt
Author: Jeff Kinne
Contents: plan/notes for the day

Questions for next time
* why WITH and not just in FROM?
* difference between INNER and NATURAL JOIN?

Questions on HW3

HW4 - inserting/creating, todo - set up your own database...

TODO: people look up DB questions on GRE and classic job interview DB 
questions, people look for DB advice blogs.

Today - more SQL, creating/inserting
* HAVING versus WHERE - 
*  see book for sequence of events.
   - where evaluated first on each row to decide which to include
   - group them (if there is a group by)
   - having restricts which groups are in the final result 

Examples - Earth Impact Database or Food Data.

CREATE TABLE meteors(
       	     id primary key auto_increment,
       	     name as varchar(100),
	     location as varchar(100),
	     lattitude as varchar(100),
	     longitute as varchar(100),
	     diameter as real,
	     age as real,
	     exposed as char(1),
	     drilled as char(1),
	     targetRock as varchar(100),
	     bollideType as varchar(100));

INSERT INTO meteors (name, location) VALUES
            	    ('Hello', 'Terre Haute');

ALTER TABLE meteors ADD comments varchar(200);

Example - creation of university database.

Views...
* queries that get run that user has access to.


Natural Join bad, instead could do
* SELECT course.course_id, title, dept_name, credits, prereq.prereq_id  
  FROM course, prereq WHERE course.course_id = prereq.course_id