Testing Conceptual Schema Satisfiability - Intentional Perspectives on Information Systems Engineering - page 273

details of the case study can be found in the report [ 25] . Section 4 summarizes the
conclusions.

2 Basic Concepts and Notation

In this section, we briefly review the main concepts and notation of the conceptual
schemas under test, and of the testing language.

2.1 Conceptual Schema Under Test

A conceptual schema consists of a structural (sub)schema and a behavioral
(sub)schema. The structural schema consists of a taxonomy of entity types (a set of
entity types with their generalization/specialization relationships and the taxonomic
constraints), a set of relationship types (attributes and associations), the cardinality
constraints of the relationship types and a set of other constraints formally defined in
OCL [13] . We adopt UML/OCL as the conceptual modeling language, but the ideas
presented here can also be applied to schemas in other languages [ 9, 15] . We are
also able to deal with temporal constraints, but for presentation purposes we omit
them here. Figure 1 shows a structural schema fragment that will be used throughout
the chapter.

0..1 0..1

ShoppingCart Customer

name : String
eMailAddress : EMail
password : String

1

1

0..1

Session
id : Natural

0..1

0..1 0..1

*

{ordered}

Order
id : PositiveInteger
/name : String
/eMail : String
/total : Real

1..*

ShoppingCartItem
quantity : PositiveInteger
/unitPrice : Real
/price : Real

Product
name : String
netPrice : Real
quantityOnHand : Integer
/quantityOrdered : Natural
/finalNetPrice : Real

* 1

1

1

{ordered} 1..*

{overlapping,incomplete}

OrderLine
/name : String
/unitPrice : Real
/price : Real
quantity : PositiveInteger

Special
specialNetPrice : Real

DownloadableProduct

*

link : URL

context Session
inv CustomerCartWhenLoggedIn :
self.customer->notEmpty() and
self.shoppingCart->notEmpty()
implies
self.customer.shoppingCart=
self.shoppingCart

context Order::total:Real
derive: self.orderLine.price->sum()

context Product inv nameIsUnique :
Product.allInstances()->isUnique(name)

Fig. 1 Fragment of the osCommerce structural schema