In general, entities are related or associated to each other. For example, a
Customer is associated with an
Customer can have one or more than one
Address (for example,
Shipping). These relationships or associations are represented differently in a relational model and the domain/object model.
In a relational model, a foreign key column represents the dependency of one table on another. The
Customer table has an
AddressId as the foreign key column, which is the primary key of the
Customer perspective, because a
Customer can have multiple addresses, so it's a many-to-one relationship. On the other hand, from the
Address perspective, one address can belong ...