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【IT168技术文档】
这里演示同一个SQL Server中不同数据库之间的基于Service Broker的异步消息传递，其中Stored Procedure充当Service Program。HelloWorldDB为目标数据库，DotNetFun2则为消息发送发的数据库。
同时，假设Server Broker的基本对象类型已经创建，如MessageType(XMLMessage), Contract(XMLContract), Queue(SendingQueue and ReceivingQueue)等等，具体操作可以参考《A simple tutorial on SQL Server 2005 Beta 2 Service Broker》。另外，因为在不同的Databases之间进行消息传递，因此需要创建Route，具体操作可以参考《SQL Server 2005 Beta 2 Service Broker: Create Route》。
1.创建Stored Procedure作为Internal Service Program.
USE HelloWorldDB GO Alter Procedure HelloWorldResponder As Begin Declare @conversationHandle UNIQUEIDENTIFIER Declare @message_body nvarchar(MAX) Declare @message_type_name SYSNAME WHILE (1=1) BEGIN BEGIN TRANSACTION -- Wait for 1 seconds for messages to arrive WAITFOR ( -- For simplicity we process one message at a time RECEIVE TOP(1) @message_type_name=message_type_name, @conversationHandle=conversation_handle, @message_body=message_body FROM [ReceivingQueue]), TIMEOUT 1000 -- If a message was received, process it, else skip IF (@@rowcount <= 0) BREAK; -- If this is a XML message, -- respond with an appropriate greeting IF @message_type_name = 'XMLMessage' BEGIN SEND ON CONVERSATION @conversationHandle MESSAGE TYPE XMLMessage ('<hello>Hello From Rickie</hello>') END CONVERSATION @conversationHandle END COMMIT END COMMIT END GO
该Stored Procedure负责从ReceivingQueue中检索消息，并根据Queue的Retention设置，来确定从Queue中移除消息或更新Queue中消息的状态。
2.设置目标队列（Target Queue）的激活机制
Use HelloWorldDB go ALTER QUEUE [ReceivingQueue] WITH ACTIVATION ( STATUS = ON, -- Turn on internal activation PROCEDURE_NAME = [HelloWorldResponder], -- Our stored proc MAX_QUEUE_READERS = 4, -- Up to 4 concurrent readers EXECUTE AS SELF) -- Execute as user of incoming dialog
设置上述创建的Stored Procedure，该Stored Procedure将被激活并处理Queue中的消息。
3.在Initiator端发送消息
Use DotNetFun2 go DECLARE @conversationHandle uniqueidentifier BEGIN TRANSACTION -- Begin a dialog to the Hello World Service BEGIN DIALOG @conversationHandle FROM SERVICE [SendingService] TO SERVICE 'ReceivingService','a727462b-52e7-4405-9eee-d19923729790' ON CONTRACT [XMLContract] WITH ENCRYPTION = OFF, LIFETIME = 600; -- Send message SEND ON CONVERSATION @conversationHandle MESSAGE TYPE [XMLMessage] ('<hello>Welcome to Rickie Lee''s blog, www.cnblogs.com/rickie</hello>'); Select * From sys.conversation_endpoints COMMIT
其中，TO SERVICE 'ReceivingService','a727462b-52e7-4405-9eee-d19923729790'，’ReceivingSerice’表示目标Service名称，'a727462b-52e7-4405-9eee-d19923729790'则指定目标Service所在的数据库，可以通过如下SQL Script获取：
-- Retrieve remote broker instance guid SELECT service_broker_guid FROM sys.databases WHERE database_id = DB_ID('HelloWorldDB')
另外，可以通过如下的SQL script来检测Initiator端收到的Reply消息：
Select cast(message_body as XML) From SendingQueue Receive message_type_name, cast(message_body as XML) From SendingQueue
4.查询对话端点状态（State of Conversation Endpoints）
最后，可以通过在Target/Initiator端查询sys.conversation_endpoints表，获取Dialog对话状态：
Select * From sys.conversation_endpoints
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