Identifying Relationships
Unique Identifiers and Normalization
• Identify relationship types
• Demonstrate steps to resolve a many-to-many relationship using an intersection entity
• Use ERDish statements to identify relationships
Vocabulary:
Directions: Identify the vocabulary word(s) for each definition below.
1. A relationship where each record in Table A can be related to one, and only one, record in Table B, and each record in Table B relates to one, and only one, record in Table A.
2. A relationship where a single record in Table A can be related to one or more records in Table B, but a single record in Table B can only be related to one record in Table A.
3. A relationship in which many records in one table match many records in another table.
4. A relationship that participates in an entity's unique identifier.
5. The product of the resolution of a many to many relationship.
Try It / Solve It:
1. Identify the relationship types (one-to-many, one-to-one, many-to-many) of the statements below:
Relationship Type Statement
A bicycle may be owned by a child
Classroom crayons may be used by students in a classroom
A female elephant gives birth to an elephant
A snowboard instructor may instruct one or more snowboarders
A driver's license belongs to a person