SqlExpression Element for ComputedField (ADF)

Specifies a valid Transact-SQL expression that computes the field value.

Syntax

<NotificationClasses>
    <NotificationClass>
        ...
        <Schema>
            ...
            <ComputedFields>
                <ComputedField>
                    ...
                    <SqlExpression>

Element Characteristics

Characteristic	Description
Data type	string, between 0 and 4,000 characters in length.
Default value	None.
Occurrence	Required once per ComputedField element.
Updates	Can be modified, but not added or deleted, when updating the application.

Element Relationships

Relationship	Elements
Parent element	ComputedField Element (ADF)
Child elements	None.

Remarks

A Transact-SQL expression is a combination of identifiers, values, and operators that the database engine can evaluate to get a result. You can use any expression that can be part of a SELECT statement. The terms of the expression can be any of the following:

• Constants.
• Calls to functions.
• The notification fields defined in the ADF (but not computed fields).
• The following built-in notification fields:
  • SubscriberId
  • DeviceName
  • DeviceTypeName
  • DeviceAddress
  • SubscriberLocale
  • DeliveryChannelName

For more information, see Expressions (Database Engine).

If you update a SqlExpression element, updating the application deletes and re-creates the notification class to which it corresponds. This includes dropping and re-creating the Microsoft SQL Server tables used by this notification class. Any data existing in the original SQL Server tables is permanently deleted.

Example

The following example shows a populated SqlExpression element. The expression here converts the stock price to the nvarchar data type.

<SqlExpression>
    CONVERT(NVARCHAR(10), StockPrice, 1)
</SqlExpression>

See Also

Reference

Application Definition File Reference

Other Resources

Defining the Notification Schema
CONVERT (Transact-SQL)
Expressions (Database Engine)
Updating Instances and Applications

Help and Information

Getting SQL Server 2005 Assistance