So far we have looked at only the simplest kind of database consisting of a single table; this is known as a flat file database. It has serious limitations when confronted by real-world tasks such as in business. It wastes space with unnecessary fields, it is difficult to maintain, it has too many openings for bad data to be entered, and so on.
The real world uses relational databases, which consist of multiple tables that are connected (i.e. they have "relationships") by means of common fields. In this section of the course you will be introduced to relational databases: you will learn how to create relationships between tables and get a sense of the great advantages relational databases have over flat file databases.
- Online Resources
- http://computer.howstuffworks.com/question599.htm -- a good explanation of relational databases
- http://youtube.com/watch?v=OGZTseZNJQk video tutorial: Creating Relationships in Microsoft Access
- http://youtube.com/watch?v=2dTT8lgWRtk -- video tutorial: Microsoft Access Relational Tables
- http://www.courses.psu.edu/infsy/infsy540_gjy1/access_tutorial_2000.html - Good step-by-step tutorial
- http://www.quasar.ualberta.ca/edit202/tutorial/database/access-rel/access-rel.htm - Good step-by-step tutorial. Includes a sample database you can download on the Provinces/Territories & Cities of Canada.
- http://cisnet.baruch.cuny.edu/holowczak/classes/2200/access/accessall.html#sec_overview - Brief overview of relational databases
- http://cisnet.baruch.cuny.edu/holowczak/classes/2200/access/accessall.html#tablerelationships
- Creating relationships between tables - http://databases.about.com/od/tutorials/l/aarelationship1.htm - Creating relationships
- http://www.fgcu.edu/support/office2000/access/tables3.html - Table relationships
- http://www.bcschools.net/staff/AccessHelp.htm#Relationships - Relationships
- http://cisnet.baruch.cuny.edu/holowczak/classes/2200/access/accessall.html#multitablequery - Querying with multiple tables
