Podcast
Questions and Answers
Which of the following is NOT a component of an ER diagram?
Which of the following is NOT a component of an ER diagram?
- Table (correct)
- Attribute
- Relationship
- Entity
In an ER diagram, a diamond shape typically represents:
In an ER diagram, a diamond shape typically represents:
- Attribute
- Relationship (correct)
- Primary Key
- Entity
What does a rectangle represent in an ER diagram?
What does a rectangle represent in an ER diagram?
- Entity (correct)
- Attribute
- Relationship
- Key
Which type of relationship is represented by a line connecting two entities with a diamond in between?
Which type of relationship is represented by a line connecting two entities with a diamond in between?
In an ER diagram, which of the following denotes a derived attribute?
In an ER diagram, which of the following denotes a derived attribute?
What is the main purpose of an ER diagram?
What is the main purpose of an ER diagram?
Which of the following is NOT a component of an ER diagram?
Which of the following is NOT a component of an ER diagram?
In an ER diagram, a diamond shape typically represents:
In an ER diagram, a diamond shape typically represents:
Which symbol is used to represent a weak entity in an ER diagram?
Which symbol is used to represent a weak entity in an ER diagram?
What does a rectangle represent in an ER diagram?
What does a rectangle represent in an ER diagram?
Which of the following best describes a primary key in an ER diagram?
Which of the following best describes a primary key in an ER diagram?
In an ER diagram, an ellipse represents:
In an ER diagram, an ellipse represents:
Which type of relationship is represented by a line connecting two entities with a diamond in between?
Which type of relationship is represented by a line connecting two entities with a diamond in between?
What is the main purpose of an ER diagram?
What is the main purpose of an ER diagram?
Flashcards are hidden until you start studying
Study Notes
ER Diagram Components
- Components of an ER diagram include entities, relationships, and attributes.
- Tables are NOT considered a component of an ER diagram.
Symbols in ER Diagrams
- A diamond shape represents a relationship between entities.
- A rectangle signifies an entity within the diagram.
- An ellipse is used to denote attributes of entities.
- A double rectangle symbolizes a weak entity.
- A dashed ellipse indicates a derived attribute.
Primary Keys and Attributes
- A primary key is defined as an attribute that uniquely identifies each entity within a table.
- Attributes can have different characteristics; they can be optional or have multiple values.
Types of Relationships
- Relationships can vary; one type involves a many-to-many connection noted by a line linking two entities with a diamond in between.
- Cardinality refers to the quantitative relationship between entities, specifying how many instances of one entity are linked to instances of another.
Purpose of ER Diagrams
- The primary purpose of an ER diagram is to represent the logical structure of a database, aiding in visualizing data relationships and organization.
- They help in the conceptual design of databases before implementation.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
