1. MIS 320 Kraig Pencil Summer 2014
Database Design
MIS 320
Kraig Pencil
Summer 2014

2. Game Plan Introduction Data base design Database scenario
Key questions/answers

3. A. Introduction Remember … ?
CNN: Internet is “Top innovation” of past 25 years (1/18/05)
But Kraig Pencil says …
The relational database is equally important
Really? Why?
The Internet would not be nearly as successful without relational databases providing rich information.

4. A. Introduction You can ask a database questions
How many cans of chicken soup do we have in inventory?
How large is the average pay raise in each department?
Who are my best/worst customers?
What else have I-Pod buyers also purchased?
Is this airline passenger a known terrorist?
Who has friended Gayle Zhang?
Who else might Gayle want to consider friending?
With the right data and a well-designed database, you can ask anything.

5. A. Introduction Who works with databases? Database programmers
Database analysts
Database designers
Database administrators
Data administrators
Website designers/programmers
Many non-IT users!
Marketers
Financial analysts
Human resources managers …. And more

6. A. Introduction What does an organization do with data/information?
Capture, cradle, and process transaction data/information
e.g., TPS
Use information to make decisions
e.g., DSS
“Oversee” the information
e.g., Who can view or use what info?, How to back up info?, How long to retain info?
What can help support the above?
A database management system

7. B. Business Scenario Is data management a problem?
For generations we stored information in filing cabinets, then in Excel spreadsheets. But as the amount of data has grown those methods have become …
Inefficient – and expensive – to store and gather data
Unable to support for decision making based on data
 A database management system is needed to support business !!!

8. B. Business Scenario Northwind Incorporated
Distributor of food and beverage products
Customers: Restaurants and specialty food stores
Suppliers: Come from around the world
In the lab and lectures, you will see how efficiently a database management system can provide rich information to the organization.

9. C. Steps of Database Design
What kinds of “things” does an organization want to collect information about?
Determine the Entities
For Northwind Inc, the “entities” of interest include:
Customers
Suppliers
Employees
Products
Etc.

10. C. Steps of Database Design (cont.)
2. What specific information about each entity is important?
Determine the attributes for each entity
Example: For the Employee entity, attributes may include
Employee name
Address
Hourly rate
Etc.
Who is this guy doing the interview?
A “business analyst”
For each employee, we keep track of …
President of Northwind

11. C. Steps of Database Design (cont.)
3. How do we organize the data? Which type of database “model” shall we use?
Assume: Use the most popular model
 Relational model
“Relation” refers to ???
Data is organized as a linked set of tables
An example of a relational database management system that you are using in MIS 320 : ___________

12. Northwind Database in MS Access
Sample Entity-Relationship Diagram (aka an “ERD” or “ER diagram”)

13. B. Database Questions (cont.)
4. What are the important aspects of a data table?
Terminology for data tables
Field (i.e. column)
Attribute of the entity
Record (i.e. row)
An instance of an entity
File (i.e., table)
Collection of records for an entity
Primary key
Unique identifier for each record
Often a unique “ID code” is created
Example: See next figure
Find all records in the Customer file for which the customer’s name field is Serena Lewis

14. Database Tables
What are examples of a) Field, b) Record, c) File, and d) appropriate Primary Key ??
Supplier Table
Supplier ID
Company Name
Street Address
City
State
1001
ACME Inc.
123 Easy St.
Deming WA
1002
XYZ Corporation
456 Maple St.
Bellingham
1003
ProductCo Inc.
389 Main St.
Seattle …
Product ID
Product Name
Unit Price ($)
Supplier ID
800
Cheddar Cheese 15
1001
801
Swiss Cheese 12
802
Chuckanut Red Wine 20
1002 … ….
Product Table

15. C. Steps of Database Design (cont.)
5. What are the relationships between the entities?
A database involves tables that are linked together
When building a database, we need to know how to link the tables
i.e., We need to know how the entities are related!
e.g., A Supplier provides a Product.
If we know who the supplier is, we can find all the products they have supplied to us.
For any product, we should be able to find the supplier’s address.
Develop a “blueprint” diagram for database design
Entity-relationship diagram

16. B. Database Questions (cont.)
5. What are the relationships between the entities? (cont.)
Possible “relationship types”
A) one to one, B) one to many, c) many to many
“one” means “at most one”
“many” means “more than one”
Example:
Entities: Supplier, Product
What is the relationship type? We are told that:
A supplier can provide many different kinds of products.
A product can be supplied by a max of one supplier.
Entity-Relationship Diagram:
one
???
many
???
Supplier
Product
Provides

17. B. Database Questions (cont.)
5. Relationship symbols: these all mean the same thing
The textbook used “crowsfoot” symbols
Access uses “1 – ∞” symbols
Access uses “ – ∞” symbols
One Many
Ignore these “inner” symbols

18. B. Database Questions (cont.)
Foreign key
Serves as a “link” between data files/tables
A field in one file/table that serves as a primary key in another file/table
How to determine the foreign key?
For a “one to many” relationship, the primary key on the “one” side of the relationship is added to the table on the “many” side
See examples

19. Database Tables: Northwest Inc.
Supplier Table
Supplier ID
Company Name
Street Address
City
State
1001
ACME Inc.
123 Easy St.
Deming WA
1002
XYZ Corporation
456 Maple St.
Bellingham
1003
ProductCo Inc.
389 Main St.
Seattle …
Product Table
Product ID
Product Name
Unit Price ($)
Supplier ID
Category ID
800
Cheddar Cheese 15
1001 10
801
Swiss Cheese 12
802
Chuckanut Red Wine 20
1002 … ….
Category ID
Category Name
Description 10
Dairy
Cheese and milk products 20
Spirits
Wine and liquors …
Category Table

20. Northwind Database in MS Access: Primary/Foreign Keys Where are the primary keys? The foreign keys?

21. C. Steps of Database Design (cont.)
6. What do we do with the entity-relationship diagram? (cont.)
ERD can be reviewed with client (Is the design correct for the client’s needs?)
Database design can be used to build the database
e.g., Build database in MS Access
Can database design get more complicated than this?
Yes!
But … the previous example will suffice for MIS 320
The lab database projects will typically focus on “one to many” types of relationships

22. Terminology Summary
The terms in each row have very similar meanings. For this course, learn all of the terms, but do not be concerned about the nuanced differences between terms in the same row.
Easy to understand
Academic
Table
(File)
Entity / Relation
Column
Field
Attribute
Row
Record
Instance