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Weak entities
Weak Entities A weak entity is an entity whose instances participate in multiple relationships with other entities. Unlike a strong entity , whose in...
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Weak Entities A weak entity is an entity whose instances participate in multiple relationships with other entities. Unlike a strong entity , whose in...
Weak Entities
A weak entity is an entity whose instances participate in multiple relationships with other entities. Unlike a strong entity, whose instances are involved in only one relationship.
Examples:
Employee is a weak entity because it participates in the customer and order relationships.
Book is a strong entity because it is involved in only one relationship (order).
Student is a weak entity because it participates in the course and registration relationships.
Key characteristics of weak entities:
They participate in multiple relationships with other entities.
They are not the focal point of the relationship.
They are indirectly dependent on other entities.
Benefits of using weak entities:
They promote modularity and data integrity.
They allow for more flexible and expressive ER models.
They help to represent complex relationships between entities