Welcome to Types of Relationships.
After watching this video, you will be able to:
• Describe the building blocks of a relationship
• Explain the symbols used in a relationship set
• Describe the difference between the one-to-one and many-to-many
relationship
The building blocks of a relationship are entities, relationship sets,
and crows foot notations.
Entity sets are represented by a rectangle.
Relationship sets are represented by a diamond, with lines connecting
associated entities.
Different techniques are used in representing relationships. For ease of
understanding, this video uses the crows foot notations. Some of these
are the greater-than symbol, the less-than symbol and a vertical line.
An Entity-Relationship diagram, or ER diagram, for the entity book would
look like this.
The entity, Book, is drawn as a rectangle, and the attributes are drawn
