serialized Dataset as message……

Greetings,

 Your problem is a complex one, so I'll address the individual problems you've raised one by one.

 First, you ask how to make BizTalk understand your dataset.  You have an XSD used to strongly type the dataset, this is good.  What you need to do is add that XSD to your BizTalk project.  This will get compiled as a Schema and can act as the definition of the message structure of BizTalk.

Next you ask how to split the individual records, process each, and gather them back at the end.  This is a very normal programmers view of the world, but isn't a particularly easy thing to do in BizTalk.  It can be done, but it is not a novice task at all.  The process of splitting your message into individual records for processing will require you to create and envelope schema.  There are some great resources at http://weblogs.asp.net/jan/archive/2004/03/07/85259.aspx which tell you how to do such a thing.  Once you've done that, to gather them all back together becomes the trick.  Assuming that order is important you'll want to implement a sequential convoy to do this.  This can be learned about here : http://www.biztalkgurus.com/Samples/Sequential-Convoy-Orchestration.html

 Now, let me give you some advice, it is generally the best practice to try and build your architecture so that each message processing through BizTalk can stand on its own.  That it does not have to be matched with other messages before sending and the like.  Spend some time to consider if your architecture can be modified to allow for that.  Sometimes it can't (EDI Batching is an example), but most times it can.  I can't tell you which position you are in because I don't know your problem.

 Tim Rayburn
http://www.TimRayburn.Net