Converting ERD to Relational Tables

Flashcards on key concepts related to converting ER diagrams to relational tables in database systems.

Entity Set

A collection of similar entities that represent real-world objects.

Strong Entity

An entity that has an independent existence and is represented by a rectangle in an ERD.

Weak Entity

An entity that cannot exist independently and has a primary key that includes a foreign key from a strong entity.

Composite Attribute

An attribute that can be divided into smaller sub-parts.

Multivalue Attribute

An attribute that can hold multiple values for a single entity instance.

Primary Key

An attribute or set of attributes that uniquely identifies each record in a table.

Foreign Key

An attribute in one table that links to the primary key of another table.

One-to-One Relationship

A relationship where one entity is associated with exactly one other entity.

One-to-Many Relationship

A relationship where one entity can be associated with multiple entities.

Many-to-Many Relationship

A relationship where multiple entities can be associated with multiple entities.

Disjoint Class Hierarchy

A class hierarchy where subclasses do not share any common instances.

Overlapping Class Hierarchy

A class hierarchy where subclasses can share common instances.