W3C XML Schema (XSD) 1.0 Reverse Engineering - Import - 7.1

Talend Data Catalog Bridges

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Bridge Requirements

This bridge:
  • is only supported on Microsoft Windows.

Bridge Specifications

Vendor World Wide Web Consortium
Tool Name XML Schema Definition (XSD)
Tool Version 1.0
Tool Web Site http://www.w3.org/XML/Schema
Supported Methodology [XML Modeling] Data Store (Physical Data Model) via XML XSD File
Data Profiling
Multi-Model Harvesting
Incremental Harvesting
Remote Repository Browsing for Model Selection

Tool: World Wide Web Consortium XML Schema Definition (XSD) version 1.0 via XML XSD File
See http://www.w3.org/XML/Schema
Metadata: [XML Modeling] Data Store (Physical Data Model)
Bridge: W3cXmlXsd version 11.0.0


Q: What schema version does this bridge support?
A: This bridge supports the W3C XML Schema 1.0 recommendation from May 2nd 2001 as defined by the following namespace in most implementations: <xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema">. If your XSD file defines a different namespace not recognized by this bridge, you could try to change it to the namespace above.
This bridge supports the Microsoft XML Data Reduced (XDR) schema, as defined by the following namespace: <Schema xmlns="urn:schemas-microsoft-com:xml-data"

Q:What schema concepts are supported by this bridge?
A: Most concepts of the W3C XML Schema 1.0 (XSD) specification such as: schema, element, attribute, simpleType, complexType, group, attributeGroup, restriction, extension, simpleContent, complexContent.
Most concepts of the Microsoft XML Data-Reduced Schema (XDR) specification, such as: Schema, ElementType, AttributeType, element, attribute, group.

Q: What are the current restrictions of this bridge?
A: The schema must not be embedded in an instance XML document, it must be located in a separate schema file.
No support yet for the W3C XML Document Content Description (DCD) standard.
Restrictions in the W3C XML Schema 1.0 (XSD) specification include:
- key and keyref which involve complex XPath syntax are not supported,
- key and keyref which fields refer to XSD attributes are supported, those referring to XSD elements are also supported provided that you set the bridge parameter 'Collapse Level' to 'Single Attribute' value or higher.
- the import mechanism is only partially supported. Imported elements are just added to the current model, generally without regards to the xml namespace.
- other unsupported concepts include unique, appInfo, redefine

Bridge Parameters

Parameter Name Description Type Values Default Scope
File The bridge uses the XML Schema file as input. FILE
Elements content name XML elements can carry some textual data, in addition to carrying named attributes and sub-elements. The XML DTD specification refers to this mixed content data as #PCDATA.
The standard bridge behavior is as follows:
- convert XSD elements into relational Entity/Table objects,
- convert XSD attributes into relational Attribute/Column objects,
- for XSD elements that contain text directly, create an extra attribute/column to carry this text, and have its name customizable with this parameter.
More advanced behaviors involve collapsing algorithms, for example to treat an XSD element as a relational attribute/column when it is used by another XSD element.
STRING   #PCDATA Mandatory
Collapse Level By default, the bridge creates a Class for every XSD element (or XDR ElementType).
To reduce the number of objects you can collapse multiple Classes together.
This option allows you to specify when to collapse a Class:
'None' - No collapsing: every XSD Element becomes a class and every XSD Attribute becomes an attribute.
'Empty' - Only empty Classes (i.e. without Attributes) should be collapsed into their parent classes.
'Single Attribute' - Only XSD elements with a single attribute and no children should be collapsed into their parent class.
'No Children' - Any XSD element that has no child element will be collapsed into its parent class.
'All' - All XSD elements for which it is possible will be collapsed into their parent class.
Single Attribute
No Children
Collapse Star Determines whether XML elements with an incoming '*' link should be collapsed into their parent class.
'True' - Collapse into their parent class.
'False' - Do not collapse into their parent class.
BOOLEAN   False  
Class Type This parameter defines how relationships between xsd elements should be interpreted. If you are converting the XSD into a UML object model, you may use this option to determine whether a Class Type (UML concept) should be created when collapsing an Element into its parent Element.
'True' - Create UML ClassTypes whenever possible. You can set this value when converting to a UML object modeling tool.
'False' - Insert the Attributes of the Element about to be collapsed into its parent's Element. Set this value when converting to a relational data modeling tool.
BOOLEAN   False  
Any Determines whether to create a Class/Entity for the 'xs:any' pseudo-element.
'True' - Represent 'xs:any' by creating a Class/Entity.
'False' - Ignore 'xs:any' altogether.

For example, in the following XSD fragment:
<xs:element name='tag' type='xs:string'/>
<xs:any minOccurs='0'/>
the xs:any content can be represented or skipped entirely.
BOOLEAN   True  
Generate IDs Determines whether additional attributes should be generated to create Primary and Foreign Keys.
'True' - Generate an Artificial Attribute for each XSD element to represent this primary key - Foreign key relationship.
'False' - The model will not contain keys.
BOOLEAN   False  
Import substitutionGroup as Allows one to specify if inheritance is represented as a generalization or if inherited attributes are duplicated (rolled down) in the subclass.
Specify 'Generalization' to represent inheritance as generalization.
Specify 'Roll down' to roll down the attributes of the parent complexType to the child complexType.
Roll down
Include Path Allows one to specify a path to a directory containing included schema files.
This option may be useful when importing a schema composed of several included xsd files.
This directory path must be locally accessible on the machine running this bridge.
If the bridge is running locally, it will always search the directory that the File parameter points to.
If the bridge is running on a remote server, this path must be a path accessible directly from the server.
UDP namespace Full name of the namespace that contains attributes to be imported as user defined properties (UDP). STRING      


Bridge Mapping

Meta Integration Repository (MIR)
(based on the OMG CWM standard)
"W3C XML Schema Definition (XSD) 1.0 Reverse Engineering"
Mapping Comments
Association Element Content Represent the links between an element and the elements it contains.
Aggregation   True unless the element is used in several complexTypes
Description annotation, documentation  
AssociationRole Element Content  
Description annotation, documentation  
Multiplicity minOccurs, maxOccurs  
Name   The source role is named after the child element of the association
Position   Position of sub-element in element content
Source   based on Elements hierarchy
Attribute Attribute, Element A particular #PCDATA attribute is created to represent the mixed content of an Element. Elements imported as a class type are also mapped as attributes
Description annotation, documentation  
InitialValue default, fixed  
Name name  
Position   Order in the file
BaseType   BaseTypes are created to serve as parents for the simpleTypes defined in the file.
CandidateKey Key Also a primary key is created if artificial attributes are generated.
Description annotation, documentation  
Name name  
UniqueKey   Always set to true
Class Element, ComplexType, Group, AtributeGroup Group, attributeGroup and complexType definitions are expanded to the element's definitions
CppClassType   Set to ENTITY
CppConcurrency   Set to True
Description annotation, documentation  
Name name  
ClassDiagram   No equivalent in XML. A main class diagram "Main" will be created to contain all elements.
ClassType Element when the Element is imported as an Attribute of its parent (depends on the bridge options).
Description annotation, documentation  
Name Element Name Element Name
DerivedType SimpleType In case of an Union, only the first item is used
DataType   See datatype conversion array
Description annotation, documentation  
Length length, totalDigits, maxLength, minLength  
LowerBound maxExclusive, maxInclusive  
Name name either explicitely in the file, or computed based on its usage
Scale fractionDigits  
UpperBound maxExclusive, maxInclusive  
UserDefined   True for simpleTypes defined in the file, False for those defined in the Schema specification
DesignPackage   No equivalent in XML. A main package "Logical View" will be created to contain all elements.
ForeignKey Keyref Foreign keys are created based on associations if artificial attributes are generated.
Description annotation, documentation  
Name name  
Grouping Sequence, Choice, All  
Description annotation, documentation  
GroupingType   GROUPING_TYPE_SEQUENCE for Sequence and All, GROUPING_TYPE_OR for Choice
Multiplicity minOccurs, maxOccurs  
Position   Position of sub-element in element content
Index   An index is created for each generated key.
IndexMember   An index member is created for each key attribute.
StoreModel Schema The model is built using the elements contained in the file.
Name   Computed from the file name.
TypeValue Enumeration  
Description annotation, documentation  
Name value  
Position   Order in the file
Value value