我在目标队列中的消息在 SQL Server Service Broker 中不可读

Question

我正在使用服务代理连接我系统中的其他域，如您在此处看到的，我向目标服务发送消息，如下所示：

_ctx.Database.ExecuteSqlCommand(@"Declare @ConversationHandle uniqueidentifier

Begin Transaction
Begin Dialog @ConversationHandle
 From Service SenderService
 To Service 'ReceiverService'
 On Contract SampleContract
 WITH Encryption=off;
SEND 
      ON CONVERSATION @ConversationHandle
      Message Type SenderMessageType
  ('<Reception>Add</Reception><OrganizationId>2</OrganizationId>') Commit");

另一方面，我让 SP 能够得到这样的消息：

ALTER PROCEDURE [dbo].[usp_ProcessTargetQueue] as
BEGIN
Declare @ConversationHandle as uniqueidentifier
Declare @MessageBody as nvarchar(max)
Declare @MessageType as sysname
declare @MessageBodyXML as xml


    WHILE (1=1)
    BEGIN

        BEGIN TRANSACTION;
        WAITFOR (
           RECEIVE top (1)
      @MessageType = message_type_name,
      @ConversationHandle = conversation_handle,
    @MessageBody = message_body
FROM TargetQueue

        ), TIMEOUT 5000;

       IF (@@ROWCOUNT = 0)
        BEGIN
              ROLLBACK TRANSACTION;
              BREAK;
        END
if @MessageType = 'SenderMessageType'
      BEGIN
            SEND 
                  ON CONVERSATION @ConversationHandle
                  Message Type ReceiverMessageType
                  ('Message is received')
            END Conversation @ConversationHandle

        set @MessageBodyXML=    (select cast(@MessageBody as xml)  )

      insert into s (s1) select CONVERT(nvarchar(max), @MessageBodyXML)

   END


        COMMIT TRANSACTION;




     END  

    END

如您所见，我将 message_body 插入到 s1 表中，但是当我检查表时，我看不到消息。

Answer 1

此代码将一个 varchar 值插入到二进制 message_body 中：

SEND 
      ON CONVERSATION @ConversationHandle
      Message Type SenderMessageType
  ('<Reception>Add</Reception><OrganizationId>2</OrganizationId>') Commit");

但这段代码将二进制值转换为nvarchar，因此该值被误解：

insert into s (s1) select CONVERT(nvarchar(max), @MessageBodyXML)

解决此问题的一种方法是指定 N 前缀，以便 xml 字符串是 Unicode 文字：

SEND 
      ON CONVERSATION @ConversationHandle
      Message Type SenderMessageType
  (N'<Reception>Add</Reception><OrganizationId>2</OrganizationId>') Commit");