Conceptual XML for Systems Analysis

Reema Al-KamhaPhD Proposal

Supported by NSF

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Motivation

Since: XML becoming standard for data representation XML Schema to specify and validate XML

documents

Thus,

Systems analysts who store their models using XML need a simple conceptual model that works with XML-based development

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Motivation

XML Schema Low-level implementation details Hierarchical structure Textual implementation

Conceptual models

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Conceptual XML (C-XML)

We have an answer to the new need of system analysts who store their models using XML!

Conceptual XML (C-XML) is a conceptual model: “Model-equivalent” with XML Schema Represents the model at a high level of abstraction

Example of usefulness: integration of XML repositories

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Thesis Statement

Conceptual-XML (C-XML) Transformation to and from C-XML and XML

Schema preserve information and constraints Integration of C-XML model instances results

in the integration of the equivalent XML schemas

Prove the concreteness of the transformations Provide prototype implementation

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C-XML

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Transformations between C-XML and XML Schema We need information- and constraint-preserving

transformations in both directions Transformations need not be inverses

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Transformation from C-XML to XML Schema

(Customer,CustomerName,CustomerAddr,Discount, (Order,OrderID,OrderDate, (Item, SalePrice, Qty)* )* )*

(Item, ItemNr,Description,Price, (PreviousItem)*,(Manufacturer,RequestDateTime,Qty)* )*

8: <xs:element name="Item"> 9: <xs:complexType> ...28: <xs:attribute name="ItemNr" type="xs:positiveInteger" use="required"/>29: <xs:attribute name="Description" type="xs:string" use="required"/>30: <xs:attribute name="Price" type="xs:decimal" use="required"/>31: </xs:complexType>32: </xs:element>

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56: <xs:group name="CustomerDetails">57: <xs:sequence>58: <xs:element name="CustomerName" type="xs:string"/>59: <xs:element name="CustomerAddr" type="xs:string"/>60: ...79: </xs:sequence>80: </xs:group>

Transformation from C-XML to XML Schema

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35: <xs:key name="OrderKey">36: <xs:selector xpath=".//Order"/>37: <xs:field xpath="@OrderID"/>38: </xs:key> ...60: <xs:element name="Order" minOccurs=“1" maxOccurs="unbounded">61: <xs:complexType>62: <xs:sequence> ...74: </xs:sequence>75: <xs:attribute name="OrderID" type="xs:positiveInteger" use="required"/> ...77: </xs:complexType>78: </xs:element>

Transformation from XML Schema to C-XML

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44: <xs:element name="Customer" abstract="true"/>45: <xs:element name="PreferredCustomer” substitutionGroup="Customer">46: <xs:complexType>47: <xs:group ref="CustomerDetails"/>48: ...49: </xs:complexType>50: </xs:element>51: <xs:element name="RegularCustomer“ substitutionGroup="Customer">52: <xs:complexType>53: <xs:group ref="CustomerDetails"/>54: </xs:complexType>55: </xs:element>

Transformation from C-XML to XML Schema

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11: <xs:element ... minOccurs="0" maxOccurs="5">

Transformation from C-XML to XML Schema

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Transformation from XML Schema to C-XML

56: <xs:group name=“CusomerDetails”>57: <xs:sequence> ...60: <xs:element name="Order" minOccurs="0" maxOccurs="unbounded"> ...77: </xs:seuence>78: </xs:group>

Algorithm overview: Generate object sets for each element, attribute Connected by relationship sets Nested according to XML hierarchy Re-code all constraints in C-XML

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Transformation from XML Schema to C-XML

Artifact of XML Schema

Artifact of XML nesting

n-ary relationshipdecomposition

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Integration

XML Schema1 XML Schema2

C-XML1 instance C-XML2 instance

Transform Transform

Integrated XML Schema

Integrated C-XML model instance

Integrated XML Schema

Tra

ns

form

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Integration

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Integration

Name

Addr

ID

ID-Nr

Month

Day

Year

Order

ConsumerDetails

Consumer

OrderDate

OrderID

Order

CustomerName

CustomerAddr

CustomerDetails

Customer

Name conflictsConstraint conflictsStructural conflictsData type conflicts

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Integration

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Data Merging

Format conflictsArbitrary lexical identifier conflicts

Units conflicts

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Produce a prototype that : Automatically transforms C-XML to XML Schema Automatically transforms XML Schema to C-XML Integrates two XML Schemas via C-XML views

Artifacts to be Produced

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Limitations of the Dissertation

No automatic mappings for schema integration No sophisticated C-XML automatic layout tools No proof that the prototype is easy to use

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Research Papers

“An Information- and Constraint-Preserving Transformation from C-XML to XML Schema”

“An Information- and Constraint-Preserving Transformation from XML Schema to C-XML”

“On the Correctness of Conceptual Level Integration of XML Schemas”

“C-XML-I: A Tool for Conceptual Level Integration of XML Schemas”

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Contribution A vision for applying conceptual modeling to

support the need of systems analysts who store their models using XML

A framework to support the vision Information- and constraint-preserving

mappings between C-XML and XML Schema Conceptual-level integration properly provides

for XML schema integration