Definicja composition (BC-DWB-TOO-BOB)

Co znaczy COMPOSITION (BC-DWB-TOO-BOB):

A relationship between object types with the meaning "is part of".

The superordinate object type in this relationship is known as the "aggregate type". In composition, the "part" object type has an extended key compared to that of the aggregate type, and completely different functions.

Example:

The object type order item "is part of" the object type order The object type order is then the aggregate type of the object type order item