Functional Dependencies

EXERCISES 1 AND 2

· 1. Using your knowledge of Premiere Products, determine the functional dependencies that exist in the following table. After determining the functional dependencies, convert this table to an equivalent collection of tables that are in third normal form.

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   Part (PartNum, Description, OnHand, Class, Warehouse, Price, (OrderNum, OrderDate, CustomerNum, CustomerName, RepNum, LastName, FirstName, NumOrdered, QuotedPrice) )

· 2. List the functional dependencies in the following table that concerns invoicing (an application Premiere Products is considering adding to its database), subject to the specified conditions. For a given invoice (identified by the InvoiceNum), there will be a single customer. The customer's number, name, and complete address appear on the invoice, as does the date. Also, there may be several different parts appearing on the invoice. For each part that appears, display the part number, description, price, and number shipped. Each customer that orders a particular part pays the same price. Convert this table to an equivalent collection of tables that are in third normal form.

·

   Invoice (InvoiceNum, CustomerNum, LastName, FirstName, Street, City, State, Zip, Date, (PartNum, Description, Price, NumShipped) )

NOTATION ON THE BOTTOM OF 162

A table that is in first normal form still might contain problems that will require you to restructure it. Consider the following table:

Orders (OrderNum, OrderDate, PartNum, Description, NumOrdered, QuotedPrice)

This table has the following functional dependencies:

OrderNum → OrderDate

PartNum → Description

OrderNum, PartNum → NumOrdered, QuotedPrice, OrderDate, Description

NOTATION FOUND ON PAGE 34

Rep (RepNum, LastName, FirstName, Street, City, State, Zip, Commission, Rate)

Customer (CustomerNum, CustomerName, Street, City, State, Zip, Balance, CreditLimit, RepNum)

Orders (OrderNum, OrderDate, CustomerNum)

OrderLine (OrderNum, PartNum, NumOrdered, QuotedPrice)

Part (PartNum, Description, OnHand, Class, Warehouse, Price)