Dagmar Kusiak

1
Chapter 2

• Dagmar Kusiak

2
Chapter Objectives

• Relational Database Terminology
• Relations (tables)
• Types of Keys
• Skip pages 41-47

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Relation

• Relation (table)
• Columns
• Unique Column names
• Primary Key (Email)
• Rows
• No identical rows (First Normal Form)

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Non-relation
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Types of Keys

• Primary Keys/Candidate Keys
• Composite Keys
• Surrogate Keys
• Foreign Keys and Referential Integrity

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Primary Keys/Candidate Keys
Primary Key Definition Unique column Candidate
Keys Definition many unique columns used to
identify a database record
Advisor(advisorID, AdvisorName, Department,
Phone, Office)
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Composite Keys
Definition key that contains two or more
columns. Candidate keys are composite. Composite
key City is not unique by itself so it contains
city, state, and zipcode.
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Surrogate Keys
Definition Special Kind of Primary Key that is
NUMERIC.
Advisor(advisorID, AdvisorName, Department,
Phone, Office)
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Foreign Keys and Referential Integrity

• Talk about Next week