Database Design Using Normalization - Database Processing: Fundamentals, Design, and Implementation - page 168

STUDENT_ACTIVITY_PAYMENT_DATA

Figure 4-6
The Denormalized
STUDENT_ACTIVITY_
PAYMENT_DATA Relation

• SKU (Primary Key)
• PartNumber (Candidate key)
• SKU_Description (Candidate key)
• VendorNumber
• VendorName
• VendorContact_1
• VendorContact_2
• VendorStreet
• VendorCity
• VendorState
• VendorZip
• QuantitySoldPastYear
• QuantitySoldPastQuarter
• QuantitySoldPastMonth
• DetailPicture
• ThumbNailPicture
• MarketingShortDescription
• MarketingLongDescription
• PartColor
• UnitsCode
• BinNumber
• ProductionKeyCode

Figure 4-7
Columns in the PRODUCT
Table

The Multivalue, Multicolumn Problem
The table in Figure 4-7 illustrates the first common problem. Notice the columns
VendorContact_1 and VendorContact_2. These columns store the names of two contacts at
the part vendor. If the company wanted to store the names of three or four contacts using this
strategy, it would add columns VendorContact_3, VendorContact_4, and so forth.

Figure 4-8
Practical Problems in
Designing Databases from
Existing Data

Practical Problems in Designing
Databases from Existing Data

The multivalue, multicolumn problem

Inconsistent values

Missing values

General-purpose remarks column