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Lesson 5: Receiving a Request and Sending a Reply

In this lesson, you will learn how to receive a request message from the target queue and send a reply message to the initiator service. Run these steps from a copy of Management Studio that is running on the same computer as the target instance of the Database Engine.

Procedures

Switch to the TargetDB database

  • Copy and paste the following code into a Query Editor window. Then, run it to switch context to the InstTargetDB database where you will receive the request message and send a reply message back to the InstInitiatorDB.

    USE InstTargetDB;
GO

Receive the request and send a reply

  • Copy and paste the following code into a Query Editor window. Then, run it to receive the reply message from the InstTargetQueue and send a reply message back to the initiator. The RECEIVE statement retrieves the request message. Then, the following SELECT statement displays the text so that you can verify that it is the same message that was sent in the previous step. The IF statement tests whether the received message is a request message type, and if a SEND statement is used to send a reply message back to the initiator. The END CONVERSATION statement is used to end the target side of the conversation. The final SELECT statement displays the text of the reply message.

    DECLARE @RecvReqDlgHandle UNIQUEIDENTIFIER;
DECLARE @RecvReqMsg NVARCHAR(100);
DECLARE @RecvReqMsgName sysname;

BEGIN TRANSACTION;

WAITFOR
( RECEIVE TOP(1)
    @RecvReqDlgHandle = conversation_handle,
    @RecvReqMsg = message_body,
    @RecvReqMsgName = message_type_name
  FROM InstTargetQueue
), TIMEOUT 1000;

SELECT @RecvReqMsg AS ReceivedRequestMsg;

IF @RecvReqMsgName = N'//BothDB/2InstSample/RequestMessage'
BEGIN
     DECLARE @ReplyMsg NVARCHAR(100);
     SELECT @ReplyMsg =
        N'<ReplyMsg>Message for Initiator service.</ReplyMsg>';

     SEND ON CONVERSATION @RecvReqDlgHandle
          MESSAGE TYPE [//BothDB/2InstSample/ReplyMessage]
          (@ReplyMsg);

     END CONVERSATION @RecvReqDlgHandle;
END

SELECT @ReplyMsg AS SentReplyMsg;

COMMIT TRANSACTION;
GO

Next Steps

You have successfully received the request message and sent a reply message to the initiator service. Next, you will receive the reply message from the initiator queue and end the conversation. See Lesson 6: Receiving the Reply and Ending the Conversation.