©2003 altova gmbh. all rights reserved. architecting xml schemas for oracle xml db september 10th,...

©2003 Altova GmbH. All Rights Reserved.

Architecting XML Schemas for Oracle XML DB

September 10th, 2003

Alexander Falk

President, CEO – Altova, Inc.Member W3C Advisory Committee


Alexander Falk Bio

► Co-founded ALTOVA in 1992

► Wrote XML Parser and XML Schema Validator used within XMLSPY

► Member of W3C XML Schema WG in 2001

► Member of W3C Advisory Committee


Agenda

► XML Schema Overview

► Schema Components

► Architecting XML Schemas

► Data Mapping & Transformations

► XML Schema & Oracle XML DB

► Tools for XML Schemas

► Live Demonstration

► Q&A


What is XML Schema?

► DTDs not sufficient for data modeling

► XML-Data, XDR, SOX, ... XML Schema

► Object-Oriented Features

Distinction between types and instances

Inheritance

Support for static vs. Dynamic types

► Make it easy to translate from programming languages to XML and vice versa


DTD‘s in a Nutshell

► Document Type Definitions (DTDs)

Uses special syntax (SGML-like)

Everything is a string (#PCDATA)

Reuse only through macros (parameter entities)

Concise syntax (although somewhat cryptic)

► Example:

<!ELEMENT Age (#PCDATA)>


Cross-Referencing XML with DTD’s

File “Person.xml” File “Person.dtd”

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE Person SYSTEM "Person.dtd">

<Person>

<First>Alexander</First>

<Last>Falk</Last>

<Age>34</Age>

</Person>

<?xml version="1.0" encoding="UTF-8"?>

<!ELEMENT Person (First, Middle?, Last, Age)>

<!ELEMENT First (#PCDATA)>

<!ELEMENT Middle (#PCDATA)>

<!ELEMENT Last (#PCDATA)>

<!ELEMENT Age (#PCDATA)>


Schema in a Nutshell

► XML Schema

Uses XML syntax

Uses Datatypes: built-in and custom-defined

Reuse through groups and inheritance

Verbose syntax (more easily readable)

► Example:

<element name=“Age” type=“integer”/>


Cross-Referencing XML with SchemasFile “Person.xml” File “Person.xsd”<?xml version="1.0" encoding="UTF-8"?>

<Person xmlns:xsi="http://www.w3.org/ 2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="Person.xsd">

<First>Alexander</First>

<Last>Falk</Last>

<Age>34</Age>

</Person>

<?xml version="1.0" encoding="UTF-8"?><xs:schema xmlns:xs="http://www.w3.org/2001/ XMLSchema"> <xs:element name="Person"> <xs:complexType> <xs:sequence> <xs:element name="First“ type="xs:string"/> <xs:element name="Middle“ type="xs:string“ minOccurs="0"/> <xs:element name="Last“ type="xs:string"/> <xs:element name="Age“ type="xs:integer"/> </xs:sequence> </xs:complexType> </xs:element></xs:schema>


XML Schema - Benefits

► Huge industry support (Oracle, BEA, Microsoft, IBM, etc.)

► Information modeling in XML

► Representing OO capabilities in XML data

► Offloading consistency checking to the validation process in the XML parser

► Cost-saving through reduced development time


Schema Components

►Elements and their content model

<element name="item"><annotation><documentation>One item of a purchase order with its

details</documentation></annotation><complexType><sequence><choice><element name="productName" type="string"/><element name="productName" type="string"/>

</choice><element name="quantity"><simpleType><restriction base="positiveInteger"><maxExclusive value="100"/>

</restriction></simpleType>

</element><element name="price" type="decimal"><annotation><documentation>Needs to be specified in

US$</documentation></annotation></element><element ref="ipo:comment" minOccurs="0" maxOccurs="5"/><element name="shipDate" type="date" minOccurs="0"/>

</sequence><attribute name="partNum" type="ipo:Sku"/>

</complexType></element>


Schema Components

►Attributes and Attribute Groups

<xs:attribute name="name" type="xs:NCName"/>

<xs:attribute name="mixed" type="xs:boolean" use="optional" default="false"/>

<xs:attribute name="abstract" type="xs:boolean" use="optional" default="false"/>

<xs:attribute name="final" type="xs:derivationSet"/>

<xs:attribute name="block" type="xs:derivationSet"/>


Schema Components►ComplexTypes and SubstitutionGroups

<xsd:complexType name="PersonType"><xsd:sequence><xsd:element name="First" type="xsd:string"/><xsd:element name="Last" type="xsd:string"/><xsd:element name="Title" type="xsd:string“ minOccurs="0"/>

<xsd:element name="PhoneExt" type="xsd:int"/><xsd:element ref="EMail"/>

</xsd:sequence></xsd:complexType><xsd:element name="Person" type="PersonType"/><xsd:element name="VIP“

substitutionGroup="Person"><xsd:complexType><xsd:complexContent><xsd:extension base="PersonType"><xsd:attribute name="IQ" type="xsd:int"/>

</xsd:extension></xsd:complexContent>

</xsd:complexType></xsd:element>


Schema Components

►Extension of ComplexType

<complexType name="Address"><sequence><element name="name" type="string“

minOccurs="0"/><element name="street“

type="string"/><element name="city" type="string"/>

</sequence></complexType><complexType name="US-Address"><complexContent><extension base="ipo:Address"><sequence><element name="state“

type="ipo:US-State"/><element name="zip“

type="positiveInteger"/></sequence>

</extension></complexContent>

</complexType>


Schema Components

►Defining your own SimpleTypes<xs:simpleType name="toddlerCounting"><xs:union><xs:simpleType><xs:restriction base="xs:int"><xs:minInclusive value="1"/><xs:maxInclusive value="3"/>

</xs:restriction></xs:simpleType><xs:simpleType><xs:restriction base="xs:string"><xs:enumeration value="many"/>

</xs:restriction></xs:simpleType>

</xs:union></xs:simpleType>


Architecting XML Schemas

► From Scratch

Using established OO methodologies, using Schema design tools, from OO class libraries (Java, C++, etc.)

► By Example (Use-Cases)

From any set of existing XML documents

► By Conversion

From existing DTD, DCD, or other schema

From SQL Database Schema


Data Mapping & Transformations

►Schema-based mapping

►Integrate data from different sources

►Web Services


XML Schema & Oracle XML DB

► XML Schema is central to Oracle 9i

► It describes how XML documents are stored inside the database

► It allows validation of XML documents in the database


Extending XML Schema for Oracle 9i

► Use SQLName to specify column names

► Use SQLType to specify storage datatype<?xml version="1.0" encoding="UTF-8"?><xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema“ xmlns:xdb="http://xmlns.oracle.com/xdb"> <xs:complexType name=“PersonType“ xdb:SQLType=“PERSON_TYPE"> <xs:sequence> <xs:element name="First“ type="xs:string“ xdb:SQLName=“FIRST_NM" xdb:SQLType=“NVARCHAR2"/> <xs:element name="Middle“ type="xs:string“ minOccurs="0" xdb:SQLName=“MIDDLE_NM" xdb:SQLType="NVARCHAR2"/> <xs:element name="Last“ type="xs:string" xdb:SQLName=“LAST_NM" xdb:SQLType="NVARCHAR2"/> <xs:element name="Age“ type="xs:short" xdb:SQLName=“PERSON_AGE" xdb:SQLType=“NUMBER"/> </xs:sequence> </xs:complexType></xs:schema>


XML Schema – Tools Overview

► Graphical Schema Editors Visual Studio .NET

xmlspy® 2004

► Mapping & Transformation Tools mapforce™ 2004

► Parsers Oracle XML DB

Xerces

MSXML 4.0 & System.XML (.NET Framework)


Demo Time

Live Demonstration


► Questions & Answers

XMLSPY, AUTHENTIC, STYLEVISION, MAPFORCE, MARKUP YOUR MIND, AXAD, NANONULL, and ALTOVA are trademarks of Altova GmbH (registered in numerous countries). All other trademarks are the property of their respective owners.

©2003 altova gmbh. all rights reserved. architecting xml schemas for oracle xml db september 10th,...

Documents