Defining identity constraints | Sybase XML instruction

Defining identity constraints

Defining identity constraints

Identity constraints enable you to indicate that element values must be unique within their specified scope.

There are three kinds of identity constraints: unique, key and keyRef.

Each identity constraint has two specific attributes: selector and field.

In a schema, an identity constraint is declared with its corresponding tag: <unique>, <key> or <keyRef>.

Identity constraints are only available in a model targeted with XSD.

Defining a unique constraint

A unique constraint specifies that an element or an attribute value (or set of values) must be unique or null within a specified scope.

For example:

Generated schema:

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Sybase XML manual Defining identity constraints, Defining a unique constraint

Contents

Sybase PowerDesigner 11.1 Last Revised June Contents Managing external shortcuts through references and data 100101 102 Working with an XML model 139 Why reverse engineer an XSD, a DTD or an XDR How to reverse engineer an XSD, a DTD or an XDR169 Mapping XML Model objects to OOM objects 171 Exchanging data with databases supporting XML 215 Vii Viii Audience SubjectDocumentation primer Conceptual Data Model User’s Guide To work with the CDM Physical Data Model User’s GuideObject Oriented Model Getting Started Business Process Model User’s Guide BeforeInsertTrigger template Typographic conventions Bibliography Xii Contents XML Model Basics Functional overview What is an XML model? Demo models About XML Objects in an XML model Tool Object Description XSD Objects in a diagram Tool Element symbol Group symbol Complex type symbol Tool Sequence symbol Choice symbol All symbol All Choosing the XML language of an XML model Defining the XML model environmentNot certified resource file ™ To change the XML language of an XML model Changing the XML language of an XML modelLanguage Description Changes concerning simple and complex types Selecting extended model definitions at model creation Option Description Defining model options XML model extended dependencies ™ To define XML model options Defining the XML model environment Defining model properties Defining an XML model™ To define the properties of an XML model Model General Property Description Model Detail Button Moves item Model ItemsTool Tooltip Description Model External Schemas Model Namespaces XML Model Basics Creating an XML model Model Preview Creating an XML model using the New model option ™ To create a new XML model using the New model option Defining an XML model List of templates Opening an existing XML model Detaching an XML model from the workspace™ To open an existing XML model ™ To detach an XML model from a workspace Saving and closing an XML model Saving an XMLModel Closing an XML model Defining an XML model Building an XML model XML diagram basics Defining an XML diagram Why build an XML diagram? Group Symbols feature Creating an XML diagramExpand/Expand All/Collapse/Arrange Symbols features Defining elements Defining element properties Element general properties Global and local elements in XDR files Defining elements XDR files Property or Element detail properties Element attributes properties Building an XML model Element mapping properties Element constraints propertiesElement Sources Attributes Mapping Creating an element™ To create an element from the palette Defining elements How to link a child object to an element? Tool Action Result Defining the attributes of an element Pointer indications Building an XML model Attribute general properties Global and local attributes in XDR files Defining attributes Attribute detail properties Attribute values Element values with XDR Adding an attribute to an element™ To add an attribute to an element Linking child elements to a parent element Modifying element display preferencesPreference Description Group particles Defining group particlesGroup particle Value of the order attribute in XDR Group particles properties Items list Creating a group particle ™ To create a group particle from an element property sheet Name and code uniqueness From the palette How to link a child object to a group particle? Clicking an element symbol with the Element tool Defining Any properties Any general properties ™ To create an Any Modifying the Any display preference Defining Any Attribute properties For example Any Attribute general properties Defining identity constraints Defining a unique constraint Unique general properties Unique fields properties Defining a key constraint Key general properties Defining a keyRef constraintKey fields properties Defining identity constraints KeyRef general properties Creating an identity constraintKeyRef fields properties Defining an identity constraint selector XPath abbreviated syntax Syntax Description Defining selector general properties ™ To display a selector property sheet Defining an identity constraint field Defining field general properties ™ To create an identity constraint field Building an XML model Defining groups Defining a group of elements Defining group properties Groups in DTD and XDR files Creating a group of elements ™ To create a group of elements from the palette Defining groups How to link a child object to a group of elements? Modifying the group display preference Defining a group of attributes Defining attribute group properties Attribute group general properties Attributes Attribute groupProperties Creating an attribute group ™ To create an attribute group from the Browser tree view Defining groups References Data types Example of shortcuts through a reference and a data type Defining simple types What is a simple type?Type of derivation Description Defining simple type properties Modifying the simple type display preferenceCreating a simple type ™ To create a simple type from the Browser tree view Building an XML model What is a complex type? Defining complex types Defining complex type properties Complex type general properties Complex type detail properties Complex type attributes properties Complex type mapping properties Complex TypeSources Icon Tool Description Modifying complex type display preferences Creating a complex type ™ To create a complex type from the palette How to link a child object to a complex type? Pointer indications Defining simple content properties Simple content™ To create a simple content General property Defining complex content properties Complex content™ To create a complex content General properties Defining derivations Deriving by extensionDerivation in element property sheet 102 ™ To define a derivation by extension Defining extension103 Restriction on a simple type Deriving by restriction104 Defining restriction facets Restriction generalRestriction detail 105 Facet general RestrictionEnumerations 106 Restriction patterns 107 ™ To create a restriction on a simple type Creating a restriction on a simple type108 109 110 Restriction on a complex type Enumeration and Pattern facets™ To create a restriction on a complex type 111 Deriving by list 112 ™ To define a simple type derivation by list Deriving by union113 Union general Union types™ To define a simple type derivation by union 114 Defining annotations 115 Defining annotation properties Defining documentation propertiesAnnotation general property Annotation items properties Documentation content Defining application information propertiesDocumentation general properties Application information general properties Creating an annotation Application information content118 119 Defining notation properties Defining notations120 ™ To create a notation from the Browser tree view Creating a notation121 Defining entities Defining entity properties122 Entity name Reference Value ™ To create an entity from the Browser tree view Creating an entity123 124 Defining import, include and redefine Defining an importDefining import properties Import general ™ To create an import from the Browser tree view Creating an import126 Defining an include Defining include propertiesInclude general 127 Defining a redefine Creating an include™ To create an include from the Browser tree view 128 Redefine general Defining redefine properties129 Creating a redefine Redefine items™ To create a redefine from the Browser tree view 130 131 What is a business rule? Defining business rulesDefining business rule properties Business rule general properties Creating a business rule Business rule expression property133 Type Description Example ™ To create a business rule from the List of Business Rules 134 Applying a business rule to an XML object 135 ™ To apply a business rule to an XML object 136 Column in the List of business rules 137 138 Working with an XML model 139 Levels of problem severity Checking an XML modelXML model check options 140 Selecting objects in the diagram XML model object selection in the Check ModelAutomatic correction 141 ™ To check an XML model Checking an XML model142 Selecting all or clearing all check boxes 143 ™ To display errors and warnings selected in the last check Displaying previously applied check options in an XML modelDockable result window 144 Making corrections based on XML model check results Display the Check toolbarContextual menu 145 Making manual corrections to an XML model Making automatic corrections to an XML model™ To make manual corrections to an XML model ™ To make automatic corrections to an XML model XML Model objects verified by Check Model Group particle checkExistence of particle Invalid cardinality Model check Identifier uniquenessUndefined identifier Shortcut code uniqueness Business rule check in an XSM Data source checkMissing namespaces Business rule name and code uniqueness File check Data source name and code uniquenessExistence of model 150 Entity check Embedded file name uniquenessExistence of external file location Entity name and code uniqueness Simple type check Include checkComplex type check Element check Existence of attributeElement name and code uniqueness Undefined type Undefined reference 154 Group name and code uniqueness Group check155 Attribute check Notation checkAttribute name and code uniqueness 156 Attribute group check Notation name and code uniquenessUndefined notation Attribute group name and code uniqueness Undefined schema location and namespace Import checkRedefine check Existence of attributes Key check Existence of componentKey name and code uniqueness Existence of fields KeyRef name and code uniqueness KeyRef check160 Unique name and code uniqueness Unique check161 Extended object check Extended link checkExtended object name and code uniqueness Extended link name and code uniqueness Replication check Extension checkRestriction check Partial object replication Existence of facet Simple type list check164 Simple type union check Annotation checkExistence of items 165 Mapping objects in an XML model Understanding object mappingDefining data sources in an XML model 166 Data source properties in an XML model Creating a data source in an XML model™ To create a data source in an XML model 167 168 Mapping XML Model objects to PDM objects Mapping elements169 XML Model object PDM object 170 Mapping complex typesTool Description 171 Mapping XML Model objects to OOM objectsXML Model object OOM object ™ To create a mapping for an element Creating a mapping for an XML object172 173 Create From Sources and Generate Mapping tools 174 ™ To modify the mapping of an attribute Modifying the mapping of an attribute175 Manipulating XML objects graphically Local objectsMove 176 Global objects Example converting a local object into a global object™ To convert a local object into a global object Drag and drop After conversions 178 Comparing and merging XML models 179 Generating an XML model from a Physical Data Model Generating XML Model objects180 PDM object Generated object in an XML model Generating and updating an XML model XML model naming conventionsGenerate new XML 181 Update existing Defining XML model generation optionsXML model Clearing the Preserve modifications check box Check model before generation 183 ™ To generate a new XML model from a PDM Generating a new XML model from a PDM184 Updating an existing XML model Generating an XML model from a package185 Preserve modifications Result Preserve modifications ™ To update an existing XML model by generating from a PDM186 Merging models 187 188 Generating an XML model from an Object- Oriented ModelOOM Object Generated object in an XML model 189 190 191 ™ To generate a new XML model from an OOM Generating a new XML model from an OOM192 193 ™ To update an existing XML model by generating from an OOM 194 195 What is a report? Editing an XML model reportCreating an XML model report ™ To create a model report 197 Language in a template Inserting diagram198 199 200 201 Why generate an XSD file? Why generate a DTD file?Why generate an XDR file? Generating an XSD, a DTD or an XDR file Defining generation parameters Check modelDefining generation targets 203 Using the Move up or down arrows Defining generation optionsDefining generation tasks 204 How to generate an XSD, a DTD or an XDR file? Parameter entities during DTD generation205 Model targeted with Generated file 206 207 What is reverse engineering? Why reverse engineer an XSD, a DTD or an XDR file?How to reverse engineer an XSD, a DTD or an XDR file? Reverse engineering an XSD, a DTD or an XDR file Reverse engineering options Reverse engineering target modelsReverse engineering to a new XML model Convert Unique References 210 211 Reverse engineering to an existing XML model 212 Auto-layout 213 214 Exchanging data with databases supporting XML 215 Why use XML in databases? 216 Mapping XML objects to PDM objects Generating an annotated schema for Microsoft SQL Server217 218 219 220 221 Extended model definitions 222 Annotated schema preview 223 224 Reinforcing mapping with extended attributes 225 226 Annotation Description 227 228 229 ™ To generate an annotated schema for Oracle Generating an annotated schema for Oracle230 231 232 233 234 235 236 Generating a DAD file for IBM DB2 ™ To generate a DAD file for IBM DB2237 Type of storage Type of mapping Description Generating a DAD file for IBM DB2 238 239 240 241 242 DAD file preview 243 244 Extended attribute Description 245 246 247 248 ™ To generate SQL/XML queries Generating SQL/XML queries249 Generating SQL/XML queries 250 251 252 253 254 Generating from an XML model 255 Generation basics Target models parameters256 Generation option Description Generating from an XML model 257 258 Generating an XML model from an XML model Why generate an XML model from an XML model?259 Generating an XML model from an XML model 260 Generating a new XML model from an XML model 261 ™ To generate a new XML model from an XML model 262 Updating an existing XML model 263 264 265 266 267 268 XSM User’s Guide 269 Union UniqueXML language XPath Index 271 PowerDesigner 272 273 274 IBM DB2 275 276 277 XML 278