Constraint Properties

Name/Code/Comment

Identify the object. The name should clearly convey the object's purpose to non-technical users, while the code, which is used for generating code or scripts, may be abbreviated, and should not normally include spaces. Neither the name nor code should contain colons. You can optionally add a comment to provide more detailed information about the object. By default the code is generated from the name by applying the naming conventions specified in the model options. To decouple name-code synchronization, click to release the = button to the right of the Code field.

Stereotype

Extends the semantics of the object. You can enter a stereotype directly in this field, or add stereotypes to the list by specifying them in an extension file.

ID

Reference

[keyrefs] Specifies the key or unique constraint being referenced. Select a constraint defined in the current model (or another model with a specified namespace).

Selector (XPath)

Enter an XPath expression that selects a set of elements across which the values specified in the Fields tab must be unique. There can only be one selector.

Keywords

Provide a way of loosely grouping objects through tagging. To enter multiple keywords, separate them with commas.

/

Root node of the XML document. It is the root element with its ramifications

.

Selects the context node. It is the current element (on which an identity constraint is defined) with its ramifications

..

Selects the context node parent

*

Selects all the child elements of the context node

employee

Selects all the employee child elements of the context node

s:employee

Selects all the employee child elements of the context node, defined in the namespace with the "s" prefix

@numEmployee

Selects the numEmployee attribute of the context node

@*

Selects all the attributes of the context node

../@numEmployee

Selects the numEmployee attribute of the context node parent

employee[1]

Selects the first employee child element of the context node

employee[last()]

Selects the last employee child element of the context node

*/employee

Selects all the employee grandchildren of the context node

//employee

Selects all the employee descendants of the root node

.//employee

Selects the employee descendants of the context node

company//employee

Selects the employee descendants of the company child elements of the context node

//company/employee

Selects all the employee elements with company as parent element in the context node

/book/chapter[2]/section[3]

Selects the third section in the second chapter of the book

employee[@dept="doc"]

Selects all the employee child elements of the context node with a dept attribute set to doc

employee[@dept="doc"][3]

Selects the third employee child element of the context node with a dept attribute set to doc

employee[3][@dept="doc"]

Selects the third employee child element of the context node only if it has a dept attribute set to doc

chapter[title]

Selects the chapter child elements of the context node with at least one title child element

chapter[title="About this book"]

Selects the chapter child elements of the context node with at least one title child element with a text content set to About this book

employee[@numEmployee and @dept]

Selects all the employee child elements of the context node with the numEmployee and dept attributes

text()

Selects all the child nodes of the text context node

XPath

For a selector: An XPath expression relative to the parent element being declared. It identifies the child elements to which the identity applies

For a field: An XPath expression relative to each element selected by the selector of the constraint. It identifies a single element (with a simple type) whose content or value is used for the constraint

Stereotype

Extends the semantics of the object. You can enter a stereotype directly in this field, or add stereotypes to the list by specifying them in an extension file.

ID