Regarding sql server notification service

Question

i never use sql server notification service. so i like to know what it does. does it notify when data changed? suppose i have one win apps by which our employee insert/update/delete data. i want that when data will be inserted/updated/deleted then this notification
service notify my win apps that data change and also provide technique to know which data change or inserted or delete. i use sql dependency but it has draw back like it can only notify client about something has happened but never say like which data is inserted
or updated or deleted.
anyone can guide me how to notify my win client from sql server with changed data like push notification with data to win client. thanks

Answer 1

can u please point me to any good article which help me to write that kind of trigger which can capture data change and push the change to client. thanks
I couldn't find an article with a cursory search so I created the example below to illustrate this basic technique that you can customize and extend for your purposes.  The trigger creates an XML document with the before/after images of the inserted/updated/deleted
rows.  The application executes the change notification target service proc in a loop to receive change messages as they become available.
This method will work for a single application instance that receives change notifications.  If you have multiple users, I suggest a mid-tier service to receive these notifications and then multicast to clients using a publish/subscribe pattern. 
In the case of frequent data changes, it would be better to use a single long-running conversation with the conversation handle saved to a state table instead of starting a new conversation for each message in order to reduce service broker overhead.
Note that the trigger will write messages to the queue regardless of whether an application is listening for messages.  For that reason, it would generally be best to run the mid-tier service continuously or at least consume/ignore all of the pending
messages at startup.
Be aware that there are a number of variations of this general pattern but I think this should get you started.  Post questions specific to Service Broker to the related forum:
http://social.msdn.microsoft.com/Forums/sqlserver/en-US/home?forum=sqlservicebroker
CREATE DATABASE ExampleDatabase;
ALTER AUTHORIZATION ON DATABASE::ExampleDatabase TO sa;
ALTER DATABASE ExampleDatabase SET ENABLE_BROKER;
GO
USE ExampleDatabase;
GO
CREATE TABLE dbo.Product(
ID varchar(50) NOT NULL
CONSTRAINT PK_Product PRIMARY KEY
, ProductName varchar(50)
, ProductDescription varchar(1000)
GO
CREATE TRIGGER TR_Product
ON dbo.Product
FOR INSERT, UPDATE, DELETE
AS
DECLARE
@ConversationHandle uniqueidentifier
,@ChangedRows xml;
SELECT @ChangedRows = (
SELECT
SELECT ID, ProductName, ProductDescription
FROM dbo.Product
FOR XML PATH('Before'), TYPE)
SELECT ID, ProductName, ProductDescription
FROM dbo.Product
FOR XML PATH('After'), TYPE)
FOR XML PATH('Changes'), TYPE
BEGIN Dialog @ConversationHandle
FROM SERVICE [ProductChangeNotificationInitiatorService]
TO SERVICE 'ProductChangeNotificationTargetService'
ON CONTRACT [ProductChangeNotificationContract]
WITH ENCRYPTION = OFF;
SEND ON CONVERSATION @ConversationHandle
MESSAGE TYPE [ProductChange]
(@ChangedRows);
GO
CREATE MESSAGE TYPE [ProductChange] VALIDATION = WELL_FORMED_XML;
CREATE CONTRACT [ProductChangeNotificationContract](
[ProductChange] SENT BY INITIATOR
CREATE TABLE dbo.ProductChangeNotificationErrors(
ErrorTime datetime NOT NULL
,conversation_handle uniqueidentifier NOT NULL
,service_name sysname
,message_type_name nvarchar(256) NOT NULL
,message_body varbinary(MAX) NULL
GO
CREATE PROCEDURE dbo.usp_CleanupProductChangeNotificationInitiatorQueue
AS
SET NOCOUNT ON;
DECLARE
@conversation_handle uniqueidentifier = '00000000-0000-0000-0000-000000000000'
,@service_name sysname
,@message_type_name nvarchar(256)
,@message_body varbinary(MAX)
,@description nvarchar(3000);
WHILE @conversation_handle IS NOT NULL
BEGIN
SET @conversation_handle = NULL;
WAITFOR (
RECEIVE TOP (1)
@conversation_handle = conversation_handle
,@service_name = service_name
,@message_type_name = message_type_name
,@message_body = message_body
FROM dbo.ProductChangeNotificationInitiatorQueue)
,TIMEOUT 1000;
IF @conversation_handle IS NOT NULL
BEGIN
IF @message_type_name = N'http://schemas.microsoft.com/SQL/ServiceBroker/EndDialog'
BEGIN
END CONVERSATION @conversation_handle;
END
ELSE
BEGIN
INSERT INTO dbo.ProductChangeNotificationErrors(
ErrorTime
,conversation_handle
,service_name
,message_type_name
,message_body)
VALUES(
GETDATE()
,@conversation_handle
,@message_type_name
,@service_name
,@message_body)
SET @description = 'Unexpected message type ' + @message_type_name + ' received';
END CONVERSATION @conversation_handle WITH ERROR = 1 DESCRIPTION = @description;
END;
END;
END;
GO
CREATE QUEUE ProductChangeNotificationInitiatorQueue
WITH ACTIVATION (
PROCEDURE_NAME = dbo.usp_CleanupProductChangeNotificationInitiatorQueue,
MAX_QUEUE_READERS = 1,
EXECUTE AS SELF);
CREATE SERVICE [ProductChangeNotificationInitiatorService]
ON QUEUE ProductChangeNotificationInitiatorQueue ([ProductChangeNotificationContract]);
CREATE QUEUE ProductChangeNotificationTargetQueue;
CREATE SERVICE ProductChangeNotificationTargetService
ON QUEUE dbo.ProductChangeNotificationTargetQueue (ProductChangeNotificationContract);
GO
CREATE PROCEDURE dbo.usp_ProductChangeNotificationTargetService
@Timeout int = 5000
AS
SET NOCOUNT ON;
SET XACT_ABORT ON;
DECLARE
@conversation_handle uniqueidentifier
,@service_name sysname
,@message_type_name nvarchar(256)
,@message_body varbinary(MAX)
,@description nvarchar(3000);
WAITFOR (
RECEIVE TOP (1)
@conversation_handle = conversation_handle
,@service_name = service_name
,@message_type_name = message_type_name
,@message_body = message_body
FROM dbo.ProductChangeNotificationTargetQueue)
,TIMEOUT @Timeout;
IF @conversation_handle IS NOT NULL
BEGIN
SELECT CAST(@message_body AS xml) AS ChangedRows;
END CONVERSATION @conversation_handle;
END;
GO
Dan Guzman, SQL Server MVP, http://www.dbdelta.com