18 Questions
What is the minimum number of Players a Team can have?
Zero
What type of entity does a Coach represent in the ER model?
Strong entity
How is the relationship between an entity and another entity represented in the ER model?
Through a primary key and a foreign key
What is the cardinality of the relationship between a Player and a Team?
Many-to-one
What is the purpose of categorizing entities as 'parent' and 'child' entities?
To determine the foreign key attribute
What is the abstraction process in the ER model?
Transforming the conceptual data model to the logical data model
What is the purpose of copying the primary key of an entity in another entity?
To represent a foreign key
In a 1:M relationship, which entity is considered the parent?
The entity with optional participation
What is the characteristic of a weak entity?
It has a copy of the primary key of another entity
In the ER diagram notation, what does the '1' in a 1:M relationship represent?
The entity with one occurrence
What is the purpose of a foreign key in the ER model?
To link two related entities
In the ER model, which type of entity has a mandatory participation in a relationship?
The child entity
What is the relationship between the Department and the Worker entities?
1:1, where the Department is the parent entity
What is the primary key attribute of the Worker entity that is copied into the Department entity?
WorkerNo
Which of the following is a characteristic of the relationship between the Team and the Player entities?
A Team can have multiple Players, but a Player can have only one Team
What is the relationship between the Player and the Parent entities?
1:N, where the Parent is the parent entity
What is the purpose of the ER diagram in the context of the local city youth league?
To design a database system for tracking children's soccer teams
What is the role of the foreign key in the relationship between the Department and the Worker entities?
It is an attribute of the Department entity that identifies the Worker
Study Notes
ER Diagram Concepts
- In a 1:1 relationship, the primary key attribute of the parent entity is copied into the child entity as a foreign key.
- In a 1:1 relationship, the determination of the parent entity depends on the relationship participation between the entities involved.
- The entity with optional relationship participation is categorized as the parent entity, and the entity with mandatory relationship participation is categorized as the child entity.
Relationship Types
- 1:1 relationship: a copy of the primary key of the parent entity is placed in the child entity as a foreign key.
- 1:M relationship: a copy of the primary key of the parent entity is placed in the child entity to represent a foreign key.
- The entity in "position 1" is the parent entity, and the entity in "many positions" is the child entity.
ER Diagram Example: Worker-Department Relationship
- In a 1:1 relationship, the Department must be managed by a Worker.
- The primary key attribute of the Worker entity is copied into the Department entity as a foreign key.
- The Department has mandatory participation in the relationship Manage.
ER Diagram Example: Youth League Soccer
- A Team may or may not have a Player.
- A Player must have a Team.
- A Team may have many Players.
- A Player has only one Team.
- A Team may or may not have a Coach.
- A Coach must have a Team.
- A Team may have many Coaches.
- A Coach has only one Team.
- A Player must have a Parent.
- A Parent must have a Player.
- A Player may have many Parents.
- A Parent may have many Players.
Learn how to design a database to manage teams, players, coaches, and parents in a sports organization. Understand the relationships between teams, players, and coaches, and how to define connectivities and participations.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
