<ComputedField> Node
Provides a location for defining one specific computed notification class field.
Structure
<NotificationClasses>
<NotificationClass>
...
<Schema>
...
<ComputedFields>
<ComputedField>
Node Characteristics
| Characteristic | Description |
|---|---|
| Occurrence | Required once or more per <ComputedFields> node. |
| Updates | Can be added and deleted using NSControl Update. |
Node Relationships
| Relationship | Elements |
|---|---|
| Parent Node | <ComputedFields> Node |
| Child Elements | <FieldName> Element (/NotificationClass/Schema/ComputedFields/ComputedField) |
Remarks
Computed fields are never stored in the notifications table. Instead, they are computed immediately before the notification data is passed to the content formatter. Computed fields allow you to make use of the formatting and calculation facilities of SQL Server. Use of computed fields can improve the performance of your notification application, and reduce the work that you must do in the content formatter. For instance, using a computed field is more efficient than calculating a field value in the Transact-SQL for a rule, because it allows you to avoid writing additional data to the notification table.
If you add or delete a <ComputedField> node, NSControl Update deletes and re-creates the notification class to which it corresponds. This includes dropping and re-creating the SQL Server tables used by this notification class.
Important When you add or delete a <ComputedField> node, any data existing in the original SQL Server tables is permanently deleted.
