Database Systems with SQL - Full Course - Database Systems - Dependency Relationships - Independent and Dependent Entities

An entity A depends on entity B only if instances of A exist in relation to instances of B. For example, an apartment belongs to a building. If the building burns down, then the apartment is gone too and could be deleted from the database. A dependent entity depends on a master entity which are related by a dependency relationship. For example Apartment-BelongsTo-Building is a dependency relationship. You can show a dependency relationship in and ER diagram by drawing an arrow pointing to the master entity. An independent entity does not depend on any other entity. For example, in a department store database, products and services are independent to each other, so they can be created without reference to any other entity. After you figure out the entities, relationships, attributes, and cardinality, database designers then determine the independent and dependent entities. For each dependent entity, the dependency relationship is identified and named. Dependent entities and dependency relationships are documented in the glossary and ER diagram. Subscribe to Appficial for more programming videos coming soon. Also, don't forget to click LIKE and comment on the video if it helped you out!