Instructor Inputs - Session 16 ppt

Instructor Inputs
Session 16

¤NIIT Instructor Inputs 16.3
This session includes Chapter 11 of the Student Guide.
Slide 1
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Querying and Managing Data Using SQL Server 2005
In this session, you will learn to:
Appreciate message-based communication
Implement Service Broker
Objectives
Begin the session by sharing the objectives with the students.
In this session, the students will learn about the benefits of message-based
communication. Further, they will learn how to implement message-based communication
using the Service Broker feature of SQL Server 2005.
Session Overview
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Slide 2
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Flash presentation:
Implementing Service Broker
Introduction to Service Broker
Use the given flash presentation to introduce message-based communication Service
Broker to the students.
Inputs for the Flash Presentation
When showing the presentation you can use the following inputs to explain the concepts:
Screen 1

This screen shows an analogy of a message-based communication. In a cargo service a
service sends messages to another service. A service is represented by a user and a
message is represented as a cargo parcel. A user sends a cargo parcel to the cargo office
near his location. The cargo parcel processes the request to deliver the message to the
other user. The first user can continue his work as he is assured that the message will be
delivered. An acknowledgement can also be sent to the user telling that the request is
processed.
Screen 2
The screen displays the communication architecture.
Mention that the Service Broker feature of SQL Server 2005 helps in implementing
message-based communication. It shows how a message is sent and processed. The
architecture shows various components that are included in communication. These
¤NIIT Instructor Inputs 16.5
components include message type, contract, service program, service, and a queue.
Explain the importance of each component using the following points:
 Message type: Specifies the type of messages that will be sent
 Contract: Defines the agreement between two services. This agreement specifies
that two services will communicate with each other. It also specifies the type of
messages that will be sent or received.
 Service program: Processes a request sent as a message.
 Queue: Stores messages. When Service Broker receives a message for a service,
Service Broker inserts the message into the queue for that service.
 Service: Participates in a communication. Each service is associated with one queue.
When a message arrives for a service, Service Broker places the message in the
queue associated with that service.
You can further explain that Microsoft SQL Server 2005 integrates Service Broker with
the database engine. It helps the database developer to build reliable, scalable, and secure
database. With Service Broker integrated with database engine, database developers can
now add the features like asynchronous communication and reliable-query processing to
the database.

Slide 3
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Is explained by the following diagram.
Introduction to Service Broker Conversation Process
Using this slide you can reiterate the communication process.
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Slide 4
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Just a minute
Which of the following objects processes a message from a
queue?
1. Service
2. Service program
3. Contract
Answer:
2. Service program
Reiterate the concept taught by asking the given question.
In the following topics, you will teach how to implement Service Broker in SQL Server.
This involves creating different objects that are used to send or receive messages.
Slide 5
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Message:
Is an entity that is exchanged between the Service Broker
services

Can contain a validation over the datatype that a message
possesses
Is of a specific message type
Message Type:
Can be created by using the CREATE MESSAGE TYPE
command
Syntax:
CREATE MESSAGE TYPE message_type_name
[ VALIDATION = { NONE | EMPTY |
WELL_FORMED_XML | VALID_XML WITH SCHEMA
COLLECTION schema_collection_name } ] [ ; ]
Let’s see how…
Creating Messages
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In this topic, you need to explain messages to the students. In addition, you also need to
explain how to create a message. You can tell that a message the data that is
communicated between two ends. A message is of a particular message type, if specified.
Otherwise, the message type is of the DEFAULT message type. You can create a message
type using the CREATE MESSAGE TYPE command. Explain the syntax of the
command.
Slide 6
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Queue:
Is an object that stores the messages
Can be viewed like a pipeline for messages
Is created by using the CREATE QUEUE command
Syntax:
CREATE QUEUE <object> [ WITH [ STATUS = { ON

| OFF } [ , ] ] [ RETENTION = { ON | OFF } [
, ] ] [ ACTIVATION ( [ STATUS = { ON | OFF }
, ] PROCEDURE_NAME = <procedure> ,
MAX_QUEUE_READERS = max_readers , EXECUTE AS
{ SELF | 'user_name' | OWNER } ) ] ]
Let’s see how…
Creating Queues
In this topic, you need to explain queues to the students. Tell the students that a queue is
represented as a table and a message acts as a row in the queue.
The row contains the content of the message as well as information about the message
type, the service targeted by the message, the contract that the message follows, the
validation performed on the message, the conversation that the message is a part of, and
information internal to the queue. An application uses the information in the message row
to identify each message uniquely and process the message appropriately.
Applications receive messages from the queue for the service. For each conversation,
queues return messages in the order in which the sender sent the message. All the
messages returned from a single receive operation are part of conversations that belong to
one conversation group. Queues do not return messages in strict first-in-first-out order.
Instead, they return messages for each conversation in the order in which the messages
were sent.
Explain the syntax of the CREATE QUEUE command.
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Slide 7
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Contract:
Is an agreement between two services that need to
communicate with each other
Specifies the type of message that will be used in a

conversation
Is created by using the CREATE CONTRACT command
Syntax:
CREATE CONTRACT contract_name
[ AUTHORIZATION owner_name ]
( { { message_type_name | [ DEFAULT ] }
SENT BY { INITIATOR | TARGET | ANY } } [
, n] ) [ ; ]
Let’s see how…
Creating Contracts
In this topic, you need to explain what a contract is and how to implement it. You can tell
that a contract specifies which message types can be used to accomplish the desired work.
The contract also specifies which participant in the conversation can use each message
type. Some message types can be sent by either participant; other message types are
restricted to be sent only by the initiator or only by the target.
Service Broker also includes a built-in contract named DEFAULT. The DEFAULT
contract contains only the message type SENT BY ANY. If no contract is specified in the
BEGIN DIALOG statement, Service Broker uses the DEFAULT contract.
Explain the syntax of the CREATE CONTRACT command.
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Slide 8
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Service:
Is used by the Service Broker to deliver messages to the
correct queue within a database
Is used to route messages, to enforce the contract for a
conversation, and to determine the remote security for a new
conversation

Is created by using the CREATE SERVICE command
Syntax:
CREATE SERVICE service_name
[ AUTHORIZATION owner_name ] ON
QUEUE
[ schema_name. ]queue_name [ (
contract_name | [DEFAULT] [ , n ] ) ]
[ ; ]
Let’s see how…
Creating Services
In this topic, you need to explain what a service is and how it is implemented in SQL
Server.
A service is an end point of conversation. A conversation in Service Broker can contain
two types of services: target and initiating. A target service represents an address that
accepts requests for the tasks identified by the contracts that the service specifies. An
initiating service represents a return address for a conversation with a target service.
Each service uses a queue to store messages. Messages sent to the service are delivered to
the queue. To create a service, you need to do the following tasks:
1. Create message types that define the data that can be sent back and forth.
2. Create a contract that identifies the message types that can be used, and which
endpoint can send them, in order to accomplish a particular task.
3. Create an application to receive, process, and send messages as necessary to
accomplish the given task.
4. Create a queue to store the incoming messages for the service. You may associate the
queue with an activation stored procedure so that the broker automatically activates
the stored procedure to process messages as messages arrive.
5. Create a service and associate it with the queue that will receive the messages for the
service.
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Slide 9

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Services communicate through a dialog.
Conversation can begin using the BEGIN DIALOG
command.
Syntax:
BEGIN DIALOG [ CONVERSATION ]
@dialog_handle FROM SERVICE
initiator_service_name
TO SERVICE 'target_service_name']
[ ON CONTRACT contract_name ]
Let’s see how…
Beginning a Conversation
In this topic, you need to explain how to begin a conversation process using the BEGIN
DIALOG command. In addition you can tell that communication between two
applications occurs through messages. As an application sends messages, Service Broker
handles the details of locating a route for the service and transmitting the message to the
target service.
Service Broker communicates the status of a conversation to an application through
messages. Service Broker indicates errors or the end of a conversation status.
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Slide 10
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Messages are sent using the SEND
ON CONVERSATION
command.
Syntax:

SEND ON CONVERSATION conversation_handle
[ MESSAGE TYPE message_type_name ] [ (
message_body_expression ) ] [ ; ]
Let’s see how…
Sending and Receiving Messages
In this topic, you will explain how messages are sent using the SEND ON
CONVERSATION command. Explain the syntax of the command.
Slide 11
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Problem Statement:
The management of AdventureWorks, Inc. wants to know the
exact yearly sales at any point of the year to help them plan
future strategies. The aggregated yearly sales data is maintained
in the SalesDetails table of the SalesDB database.
The sales transaction details are stored in the SalesOrderHeader
and SalesOrderDetails tables in the AdventureWorks database.
To keep the yearly sales data updated, you need to ensure that
whenever any order is processed and its shipping date is
updated in the AdventureWorks database, the total monetary
value of that order, stored in the SubTotal column of the table,
should be added to the total yearly sales in the SalesDB
database.
Demo: Implementing Service Broker
At the end of this activity, the students will be able to implement asynchronous
communication using Service Broker in the database.
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Note
For this activity, you need to create another database, named SalesDB. To create this

database, you can use the createSalesDB.sql data file given in the
Datafiles_for_faculty\QMDS2005\Chapter 11\Activity folder in the TIRM CD.
When demonstrating this activity, you can use the Demo1.txt file provided in the
Datafiles_for_faculty\QMDS2005\Chapter 11\Activity folder in the TIRM CD. This file
contains all the commands that you need to type for various tasks involved in the
solution. You can directly copy the commands from this file and execute them in the
Query Pane.
Slide 12
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Solution:
To solve the preceding problem, you need to perform the
following tasks:
1. Create a service program.
2. Create message types, contract, queues, and service objects.
3. Create a trigger on the SalesOrderHeader table.
4. Verify the functionality.
Demo: Implementing Service Broker
You can also check that the transaction is committed even if the database is not available
by detaching the database. Next, you can execute the INSERT statement in the
Sales.SalesOrderHeader table in the AdventureWorks database. The record will be
inserted in the table even if the SalesDB database is not available. Finally, you can again
attach the SalesDB database. After attaching the database, you will notice that the sales
amount will be added to the total yearly sales amount.
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Slide 13
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In this session, you learned that:
Service Broker provides a platform that allows the developers
to create asynchronous and reliable query processing.
In Service Broker, the developers create services that
converse with each other by sending and receiving messages.
A message is data exchanged between services.
Each message is of a specific message type.
A service is a database object that provides an endpoint for a
conversation.
A contract is an agreement between the services that
participate in a conversation.
Each service is associated with a queue that acts as a
container that stores messages.
A service program provides the required service to which a
message is forwarded by the queue for processing.
Summary
Summarize the session.
Slide 14
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When implementing Service Broker, you need to create
message, queue, contract, service, and conversation database
objects.
A message can be created by using the CREATE MESSAGE
TYPE command.
A queue can be created by using the CREATE QUEUE
command.
A contract can be created by using the CREATE CONTRACT
command.

A service can be created by using the CREATE SERVICE
command.
A conversation can be started by using the BEGIN DIALOG
command.
Messages can be sent by using the SEND ON
CONVERSATION command.
Summary (Contd.)
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