1. ER Example Expressed as IMM Core Instance Specifications
Formerly Data Access Technologies
ER Example Expressed as IMM Core Instance Specifications
Jim Logan
3/12/2008

2. Copyright © 2008 Model Driven Solutions.
Agenda
Why a core metamodel?
IMM metamodel core parts
Transforming among technology metamodels
ER example instances in the core
March 2008
Copyright © 2008 Model Driven Solutions.

3. Copyright © 2008 Model Driven Solutions.
Why a Core Metamodel?
Unifies technology-specific metamodels with a hub and spoke pattern instead of a full mesh
Represents common concepts
Transformation between technology-specific models becomes simpler
March 2008
Copyright © 2008 Model Driven Solutions.

4. IMM Metamodel Core Parts
Common concepts:
Attribute
Association
Thing Type
Mix-in concept library:
Identifier specification
Reference
Reference Attribute Binding
Composition
Technology-specific concepts:
Relational examples: Table, Row, Column, Primary Key, Foreign Key
XML Schema examples: Element, Complex Type, Sequence, Group
Common
Mix-in
Separate Metamodels
Technology-specific
March 2008
Copyright © 2008 Model Driven Solutions.

5. Transforming Among Technology Models
Pivot through Core Unchanged
Common
Mix-in
Technology-specific ER
RDB
March 2008
Copyright © 2008 Model Driven Solutions.

6. ER Model: Entity Type and Attribute
Entity types
Attributes
March 2008
Copyright © 2008 Model Driven Solutions.

7. Core: Identifiable Type and Attribute
March 2008
Copyright © 2008 Model Driven Solutions.

8. Core Instances: Identifiable Type and Attribute
ER domains become specializations, possibly with additional constraints
March 2008
Copyright © 2008 Model Driven Solutions.

9. ER Model: Relationships
A property of an entity type is either an attribute or a role
Associative Relationship
Binary Roles
Generalization Relationship
March 2008
Copyright © 2008 Model Driven Solutions.

10. Copyright © 2008 Model Driven Solutions.
Core: Association
March 2008
Copyright © 2008 Model Driven Solutions.

11. Core: Static Generalization
March 2008
Copyright © 2008 Model Driven Solutions.

12. Core Instances: Association and Generalization
March 2008
Copyright © 2008 Model Driven Solutions.

13. Copyright © 2008 Model Driven Solutions.
ER Model: Identifiers
Identifiers
March 2008
Copyright © 2008 Model Driven Solutions.

14. Core: Identifier Specification
March 2008
Copyright © 2008 Model Driven Solutions.

15. Core Instances: Identifier Specification
March 2008
Copyright © 2008 Model Driven Solutions.

16. Copyright © 2008 Model Driven Solutions.
Virtual Entity Types
A SUPPLIER is defined as a PARTY who is not us and is a seller in an ORDER.
Virtual Entity Types
A CUSTOMER is defined as a PARTY who is not us and is a buyer in an ORDER.
March 2008
Copyright © 2008 Model Driven Solutions.

17. Core: Conditional Generalization
March 2008
Copyright © 2008 Model Driven Solutions.

18. Core Instances: Conditional Generalization
March 2008
Copyright © 2008 Model Driven Solutions.

19. Copyright © 2008 Model Driven Solutions.
Derived Attributes
LINE ITEM.Value = INFER (PRODUCT TYPE.Price, for PRODUCT TYPE) * LINE ITEM.Quantity
ORDER.Total Value = SUM (LINE ITEM.Value, composed of LINE ITEM)
Derived Attributes
March 2008
Copyright © 2008 Model Driven Solutions.

20. Core: Value Specification
March 2008
Copyright © 2008 Model Driven Solutions.

21. Core Instances: Value Specification
March 2008
Copyright © 2008 Model Driven Solutions.