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Subscription Schema Examples

When you define a subscription class, you can define the schema for subscription data. This topic shows several examples of which fields you might define in different scenarios. For more information about subscription schemas, see Defining the Subscription Schema.

Note

The following examples show the values that are used to define subscription class fields. Exactly how you define the fields depends whether you are using XML or NMO to define the application.

Per-Subscription Devices and Locales

This schema is for a weather application. When a subscriber creates a subscription, the subscriber must specify the city for weather forecast notifications. The subscriber must also select a device and a locale for notification delivery.

The schema for this scenario contains three fields: DeviceName, SubscriberLocale, and City.

Field name Field type Field modifiers

DeviceName

nvarchar(255)

NOT NULL

SubscriberLocale

nvarchar(10)

NOT NULL

City

nvarchar(35)

NOT NULL

Pre-Defined Device Name and Locale

This schema is for a flight application. When a subscriber creates a subscription, the subscriber must specify the code for the city of origin, the code for the destination, and a trigger price for notifications. The subscriber can also specify a carrier. If no carrier is specified, the subscriber will receive notifications for all carriers.

This application supports only one device and one locale. Therefore, the device name and locale can be specified in the Transact-SQL query that is used to generate notifications. There is no need for DeviceName and SubscriberLocale fields in the subscription schema, unless there are plans to support multiple devices and locales in the future.

Field name Field type Field modifiers

LeavingFrom

nvarchar(6)

NOT NULL

GoingTo

nvarchar(6)

NOT NULL

Carrier

nvarchar(255)

 

Price

float

NOT NULL

Per-Subscription Device, Pre-Defined Locale

If the flight application is changed to support multiple devices, but not multiple locales, you would add a DeviceName field to the schema definition.

Field name Field type Field modifiers

DeviceName

nvarchar(255)

NOT NULL

Origin

nvarchar(6)

NOT NULL

Destination

nvarchar(6)

NOT NULL

Carrier

nvarchar(255)

 

Price

float

NOT NULL

Note

If you alter a subscription class and update the application, the existing subscription tables are renamed and new subscription tables are created. You can migrate subscription data from the old to the new tables. For more information, see Updating an Application.

No Custom Fields

The following field definitions are for a subscription class that either sends the same notification to everyone, or supports condition actions in which subscribers define complex conditions over event fields. The user does not provide values for any WHERE clause parameters, but must select a device and a locale.

Field name Field type Field modifiers

DeviceName

nvarchar(255)

NOT NULL

SubscriberLocale

nvarchar(10)

NOT NULL

If an application does not have custom fields and does not support multiple devices and locales, the subscription class has no schema.

See Also

Reference

SubscriptionFields

Concepts

Defining the Subscription Schema

Other Resources

Data Types (Database Engine)
CREATE TABLE (Transact-SQL)
FieldTypeMods Element for SubscriptionClass/Schema/Field (ADF)
FieldType Element for SubscriptionClass/Schema/Field (ADF)
Schema Element for SubscriptionClass (ADF)

Help and Information

Getting SQL Server 2005 Assistance