Define an Entity-Relationship model

3 Define an Entity-Relationship model

Exercise 5: Specify an example ER diagram for an insurance scenario. An insurance policy has a customer, a premium, a start date, and an end date. Customers have names and addresses. A claim has a description and is referring to an insurance policy.

Customer in EntityType with
  attr
    name: String;
    address: String
end

Policy in EntityType with
  attr
   startdate: Date;
   enddate: Date;
   premium: Integer
end

holds in RelationshipType with
  role
    customer: Customer;
    policy: Policy
end

Claim in EntityType with
  attr
    description: String
end

claim_policy in RelationshipType with
  role
    claim: Claim;
    policy: Policy
end

Figure 3 graphically displays the insurance model. ConceptBase can also assign dedicated graphical symbols to certain objects, e.g. diamond shapes to relationship types. We skip this feature in this tutorial and refer you to the user manual for more details on this.

The green links are instantiations. Hence the insurance model is one abstraction level below the ER language.

Figure 3: The insurance model as instantiation of the ER language