EF4 - How to "attach" entities from different ObjectContext's together, to save them all in the same transaction?

I want to create the app modular and would like to create multiple EDMX, with just the subset to tables needed in that specific context.

E.g.

• an EDMX for Invoics: Invoice table, InvoiceDetails, Customer
• an EDMX for Orders: Order table, OrderDetails, Customer
• etc.

This way I keep things smaller and manageable (I think)

But I might need to create a generic module that performs a batch operation on several entities, possible spread across multiple EDMX. E.g. Consolidate clients - merge multiple clients to a single client (maybe users entered same client by mistake multiple times, or I want to merge two client accounts,etc)

For this I want to use Se开发者_JAVA技巧rviceLocator pattern

1. define an interface, IClientMerger
2. and as I create a new entity that refer to client, I also create a new IClientMerger handler
3. when I need to deduplicate, I load all ICLientHandlers, and call them in a loop, and they replace the old ClientID with new ClientID in handled entity (one in Invoices, one in Orders, etc.)

All is fine, but I want to pack this all in a transaction, so all will get saved or not. being in separate EDMX, how can I pack them all in a single transaction? Should I manually create a ADO.NET transaction and call objectContext.SaveChanges for all EDMX inside? Or there's another, more elegant way?

Thanks

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using(TransactionScope tran = new TransactionScope())
{
  //do some work...
  context1.SaveChanges()
  context2.SaveChanges()

  tran.Commit()
}

If there's no Commit before the TransactionScope is disposed, the transaction is automatically rollbacked.

The contexts can even work on differents sql servers if MS DTC is available.

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Try the TransactionScope class.
You will need the Required TransactonScopeOption.