How to identify a strong vs weak relationship on ERD?

Question

A dashed line means that the relationship is strong, whereas a solid line means that the relationship is weak. On the following diagram how do we decide that the relationshi

Answer 1

1. Weak (Non-Identifying) Relationship

   • Entity is existence-independent of other enties

   • PK of Child doesn’t contain PK component of Parent Entity

2. Strong (Identifying) Relationship

   • Child entity is existence-dependent on parent

   • PK of Child Entity contains PK component of Parent Entity

   • Usually occurs utilizing a composite key for primary key, which means one of this composite key components must be the primary key of the parent entity.