Weak entity

In a relational database, a weak entity is an entity that cannot be uniquely identified by its attributes alone; therefore, it must use a foreign key in conjunction with its attributes to create a primary key. The foreign key is typically a primary key of an entity it is related to. In IDEF1X, a government standard for capturing requirements, possible are: * Complete subtype relationship, when all categories are known. * Incomplete subtype relationship, when all categories may not be known.

Weak entity

In a relational database, a weak entity is an entity that cannot be uniquely identified by its attributes alone; therefore, it must use a foreign key in conjunction with its attributes to create a primary key. The foreign key is typically a primary key of an entity it is related to. In IDEF1X, a government standard for capturing requirements, possible are: * Complete subtype relationship, when all categories are known. * Incomplete subtype relationship, when all categories may not be known.