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Defining identity constraints
Defining field general properties
The General page of a field property sheet displays the following properties:
Property | Description |
XPath | An XPath expression relative to each element selected by the |
| selector of the identity constraint. It identifies a single element |
| (with a simple type) whose content or value is used for the |
| identity constraint |
Stereotype | |
| without changing its structure. It can be predefined or user- |
| defined |
ID | ID of the field. Its value must be of type ID and unique within |
| the model containing the field |
|
|
To create an identity constraint field:
1Click the Fields tab of an identity constraint (unique, key or keyRef) property sheet.
2Click any empty line in the Fields page.
An arrow appears at the beginning of the line.
3Type an XPath expression.
4Click Apply.
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74 | PowerDesigner |