1. CS 3630 Database Design and Implementation

2. Design Methodology Three main phases
A structured approach that uses procedures, techniques, tools, and documentation aids to support and facilitate the process of design.
Three main phases
Conceptual database design
Understanding client data
E-R (EER) Model
Agreement between clients and designers
E-R Model could be used for any database system
Logical database design
Mapping E-R Model to (relational) database schema
Normalization
Physical database design
2013: Finished at 43 for both sections

3. Mapping E-R Model to Relational Database Schema
Entity type  Table schema
How to maintain relationships?

4. Mapping Strong Entities to Relation (Table) Schemas
Replacing composite attributes with simple attributes
Adding new tables to remove multi-value attributes

5. Replacing Composite Attributes with Simple Attributes
Name: Composite (FirstName, LastName)
Use two attributes:
FirstName
LastName
Address : Composite (Street, City, State, Zipcode)
Use four attributes:
Street
City
State
Zipcode
Performance issue

6. Composite Attributes Search/Project on state or zip code staffNo Name
Address
. . .
SL21
John White
1 main street, Platteville, WI 53818
SG37
Ann Beech
15 University Dr, Madison, WI 53706
SA9
Mary Howe
908 Western avenue, Dubuque, IA
Search/Project on state or zip code

7. Simple Attributes Search/Project on state or zip code staffNo
firstName
lastName
Street
City
State
zip
SL21
John
White
1 main street
Platteville WI
53818
SG37
Ann
Beech
15 University Dr
Madison
53706
SA9
Mary
Howe
908 Western avenue
Dubuque IA
Search/Project on state or zip code

8. E-R Model
Staff StaffNo Name: Simple or Composite? Address Salary . . .

9. Removing Multi-Value Attributes
No multi-value attributes in relational databases
First Order Logic
No sets as set elements

10. Multi-Value Attributes
branchNo
street
city
state
zipCode
telNo
B001
1 main street
Platteville WI
53818
B002
15 university drive
Madison
53706 …

11. Removing Multi-Value Attributes without Losing Data
Entity Type in E-R Model
Branch
branchNo
. . .
telNo: multi-value
How to Store telNo?
phoneOne
phoneTwo
phoneThree
(When we know the limit of phone numbers at a branch: at most three)
Staff
staffNo
homePhone
workPhone
cellPhone

12. Each Branch Has at Most Three Phone Numbers
branchNo
street
. . .
phone1
phone2
phone3
B001
1 main street
B002
15 university drive …

13. Home Phone, WorkPhone and Cell Phone
staffNo
street
. . .
homePhone
workPhone
cellPhone
SL21
1 main street
SG37
15 university drive
SA79 …

14. Multi-Value Attributes Without Limit
Entity Type in E-R Model
Branch
branchNo
. . .
telNo: multi-value (NO LIMIT or LIMIT TOO LARGE)
More Examples
Student Major
Work Experience
Research publications

15. Replacing Multi-Value Attributes
branchNo
Street
City
State
zipCode
B001
B002 …
branchNo
. . .
telNo
B001
B002 …
branchNo
telNo
B001
B002 …
One table  two tables
Multi-Value attribute  multiple records
Primary Key  Foreign Key

16. Replacing Multi-Value Attributes
Entity Type in E-R Model
Branch
branchNo
. . .
telNo: multi-value (NO LIMIT!)
How to Store telNo?
Remove it from Branch and create a new table!
BranchPhone
telPhone
Which attributes should be in the new table?
The PK attribute(s) and the multi-value attribute.
Is branchNo the PK in Branch?
Is branchNo the PK in BranchPhone?
Foreign Key!

17. Primary Key and Foreign Key
branchNo
telNo
B001
B002 …
branchNo
Street
City
State
zipCode
B001
B002 …

18. What is the Primary Key? BranchPhone branchNo telPhone Assumption
Two branches don’t share the same phone #
Two branch can shared the same phone #
(branchNo, telephone)
newAtt
Must be unique!

19. Replacing Multi-Value Attributes
Always use a new table to replace any multi-value attribute IN Assignments Quizzes Tests Final

20. Mapping Entity Type to Table Schema
Entity Type in E-R Model
Branch
branchNo
address: composite (street, city, state, zipCode)
telNo: multi-value (with or without limit!)
Table Schema (DBDL)
Branch (branchNo, street, city, state, zipCode)
PK: branchNo
AK: street, city, state, zipCode
FK: NONE
BranchPhone (newAtt, branchNo, telPhone)
PK: newAtt
AK: NONE
FK: branchNo references Branch

21. Mapping Entity Type to Table Schema
Entity Type in E-R Model
Staff
staffNo
. . .
DOB
workExperince: multi-value
Composite (start, end, org, position)
Store workExperince with staffNo in a new Table!
WorkExperience
start
end
org
position
PK?
Could create a new PK attribute (workExpID)
FK?

22. Storing Work Experience
Entity Type in E-R Model
Staff
staffNo
. . .
DOB
workExperince: multi-value
Composite (start, end, org, position)
Table Schema (DBDL)
Staff (staffNo, . . ., DOB)
PK: staffNo
AK: NONE
FK: NONE
WorkExperience(workExpID, staffNo, start, end, org, position)
PK: workExpID
AK: None
FK: staffNo references Staff

23. Individual Assignment Due Wednesday, Feb 22