Entities RDBMS representation
Entities overview
The modeling support of IBM Financial Services Workbench is based on Domain Driven Design and lets you model different kinds of entities:
Root Entity: the main aggregate object that is defined not by its attributes, but its identity
(Value) Entity: an object that contains attributes but has no conceptual identity
External Entity: an entity that acts as a reference to another entity, but also holds some identifying properties of its own
Entity relationships example
Mapping in RDBMS
Root Entity
Mapped to its own tables with support for One-To-Many and One-To-One Foreign Key relationships with other root entities.
(Value) Entity
Common use case as value objects, input to commands, services, etc.
If modelled as a property of a root entity, its data will be embedded in the root entity's table. In case of a collection (list of value entities), a collection table will be created and linked with root entity.
External Entity
Common use case as reference to an entity that resides outside the domain (or even within an external system). The same embedded strategy that applies to value entities will be applied here.
Mapping Example
