DD Class11

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More Normal Forms

Second Normal Form

In order to reach 2NF the table must first be in 1NF

Second Normal Form eliminates functional dependencies on a partial key by putting the fields in a separate table from those that are dependent on the whole key.

'Remove Fields that are not dependent on the primary key'

Not Normal


CustNum FirstName LastName Address City State ZIP
1 John Doe 12 Main Street Sea Cliff NY 11579
2 Alan Johnson 82 Evergreen Tr Sea Cliff NY 11579
3 Beth Thompson 1912 NE 1st St Miami FL 33157
4 Jacob Smith 142 Irish Way South Bend IN 46637
5 Sue Ryan 412 NE 1st St Miami FL 33157



ZIP City State
11579 Sea Cliff NY
33157 Miami FL
46637 South Bend IN


CustNum FirstName LastName Address ZIP
1 John Doe 12 Main Street 11579
2 Alan Johnson 82 Evergreen Tr 11579
3 Beth Thompson 1912 NE 1st St 33157
4 Jacob Smith 142 Irish Way 46637
5 Sue Ryan 412 NE 1st St 33157

In class

Normalize the books exmaple


Author Title Pages Publisher PublisherURL Subject ISBN
Michael Allen Dymmoch The Man Who Understood Cats 256 Avon Books http://www.harpercollins.com/imprints/index.aspx?imprintid=517994 Fiction Mystery 0380722658
Joseph Cancellaro Exploring Sound Design for Interactive Media 272 Thomson Delmar Learning http://www.delmarlearning.com/ Sound 1401881025

Third Normal Form

Third Normal Form eliminates functional dependencies on non-key fields by putting them in a separate table. At this stage, all non-key fields are dependent on the key, the whole key and nothing but the key. Must be in second normal form.

Not normal

Company City State ZIP
Acme Widgets New York NY 10169
ABC Corporation Miami FL 33196
XYZ, Inc. Columbia MD 21046


KompanyID KompanyName Zip
1 Acme Widgets 10169
2 ABC Corporation 33196
3 XYZ, Inc. 21046

Zip CityID
10169 1
33196 2
21046 3

CityID City
1 New York
2 Miami
3 Columbia

StateID State
1 NY
2 FL
3 MD


Many to Many Relationships

Look up tables. Are often used to define a many to many relation ship. These lookup tables often have a compound key.

See the Student Courses example from the Data Relationships page.

This is a demonstration of a logon system where users can have multiple roles. There is a compound key used on the roles table. The compound key consists of two or more foreign keys. Each combination of foreign keys must be unique.


Lookup Table

Here the BlogTags Tbale uses a compound key (two primary keys) to join two other tables. The Blog table is joined to the Tag table where each person can add a tag. This is a one to many one to many relationship. Person can a tag to each blog. This is often referred to as a look up table


Logon Using the tables in blog

You can use the Authorization Section of web.config to protect file or a directory. You can have more than one web.config in a project also. You can have one for each folder. The web.config setting inherit from the parent folder and most section can be overridden. Here is an example of a small web.config that protects a folder call admin with the .net authentication mechanism.


Main web.config add the following to the system.web section <xml> <system.web>

    <authentication mode="Forms">

<forms loginUrl="classsource/logon/logon.aspx" name="adAuthCookie" timeout="20" path="/" protection="All"> </forms>



Now any link to the admin folder


should redirect to the logon page

Logon Page

http://iam.colum.edu/dd/classsource/Logon/Logon.aspx - source http://iam.colum.edu/dd/gbrowser.php?file=/classsource/Logon/Logon.aspx.cs

Add a New user page http://iam.colum.edu/dd/classsource/Logon/CreateAccount.aspx -source http://iam.colum.edu/dd/gbrowser.php?file=/classsource/Logon/CreateAccount.aspx.cs

Admin Page http://iam.colum.edu/dd/classsource/Logon/Admin/Default.aspx - source http://iam.colum.edu/dd/gbrowser.php?file=/classsource/Logon/Admin/Default.aspx.cs

Logon the Microsoft way


Create a many to many relationship with games. Create a web interface that can add and remove games from genres.