Announcements n No class on Thursday Time to get together with your group and work on the project n Office Hours this week: Today: 1:00 to 1:30 Wednesday:

Announcements

No class on Thursday• Time to get together with your group and work

on the project Office Hours this week:

• Today: 1:00 to 1:30• Wednesday: 10:00 to 11:00• Friday: 1:30 to 2:30

Practice ExerciseNormalize Payment Voucher

Payment Voucher

Payment Voucher

First Normal Form• Select and define data elements of interest• Eliminate repeating groups• Identify primary key• Business Process Assumptions

Primary Key?

One from non-repeating section• PV-Num

One from each repeating section• ProdCode• RRNum

Second Normal Form

Is the FNF table in Second Normal Form?• Why or why not?

If not, what are the functional dependencies? What business process assumptions did you

make?

Second Normal Form

Required since concatenated primary key• Seven combinations

– PVNum ProdCode RRNum– PVNum + ProdCode– PVNum + RRNum– RRNum + ProdCode– PVNum + ProdCode + RRNum

Functional Dependencies

Corresponding Documents Table

Is this table in second normal form?

Third Normal Form

Are the SNF tables in Third Normal Form?• Why or why not?

If not, what are the transitive dependencies? What business process assumptions did you

make?

SNF Tables

Third Normal Form

Transitive dependencies?• Supplier Information

– PVNum identifies Supplier Name– Supplier Name identifies Supplier Shipping Address,

CSZ?

PV Normalized Schema

Common Tables?

ZipCityState (all 3) Product (all 3) Supplier Shipping Location (PO & RR) Supplier Sales Office (PO & PV) Receiving Report Detail (RR & PV)

Database Schema for Purchasing Cycle

These are the tables and relationships used to generate the Purchase Order, Receiving Report, and Payment Voucher

Assignment Design Third Normal Form Datadase for Order

Fulfillment of CRC • You must be able to create these reports from data

within the tables. – Sales Order Confirmation– Bill of Lading– Backorder Notice

• Focus on the data, not the process– Do not worry about what triggers the Backorder Notice,

just be able to create the report from the underlying tables

Assignment Once you have designed the tables:

Use Access to document the relationships between the tables and as your data dictionary Create empty tables in Access Enter the abbreviated field names, specify the data

type and size, enter the long name as the caption Set the primary key fields

Assignment Use the “relationships” feature in Access to

define the relationships between tables Always set to enforce referential integrity

Assignment Provide a description of the processes that

you used to design the third normal form tables. Specifically: You must justify your selection of fields for the

primary keys You must describe how you know that each table

is in third normal form. Provide all assumptions you had to make

regarding the nature of the business operations to support the placement of the various data elements within the tables.

Review

What is normalization and why is it important to normalize a database?

Distinguish between First, Second and Third normal forms.

What are the characteristics of a “primary key”? 

What does it mean when there is a “one to many” relationship?

What is a "foreign key"?