We have an EntityBase base class which all our entities inherit from. We use fluent nhibernate and map the ID column of the base class as follows (you also need a version column if you are assigning your own id value):
Id(e => e.ID).GeneratedBy.Assigned();
Version(x => x.Version).UnsavedValue(“0″);
Then in the constructor of the entity base class we set the ID using a sequential GUID (quicker to access when querying db) using:

protected EntityBase()
{
ID = SequentialGuid();
}

[DllImport("rpcrt4.dll", SetLastError = true)]
static extern int UuidCreateSequential(out Guid guid);

public static Guid SequentialGuid()
{
const int RPC_S_OK = 0;
Guid g;
if (UuidCreateSequential(out g) != RPC_S_OK)
return Guid.NewGuid();
else
return g;
}

The ID can be overwritten if required (as in the above case where you are asking a command to create an entity with a specific id)

As I say I will post more readable code on our blog once I get a chance…

1. Web Page with field to create a new customer

2. MVC Controller action for Save

3. Create Command with details from form – Including a new GUID created in the controller and passed to the command object like the form arguements.

4. Get Handler for Command

5. Execute Command

6. Redirect to display new details on Say a Update page ie Controller Action Update in Get Mode.

I assume with NHibernate your using GUIDs for you Identity and no GENERATOR just GENERATOR ASSIGNED type in NHibernate.

Is this correct?

Thanks.

If you’re using integers for your ids, than using a hi/lo implementation would be my next suggestion.

I would not recommend using an auto incrementing identity column in your database for your id (which I’m guessing you’re doing) At that point, you’re application no longer has control over the id generation. Then you’ll need to use a correlation identifier as Jimmy suggested.

On this application, we are not strictly following the CQS (though I with they looked more like what Jimmy is describing). I’ll try to work up an example of both.

They run synchronously and return success or failure, any error messages and whatever data needs to be generated.

Blair

If I do not know the Id of the newly saved customer how do I perform step 6?

Thats my point.

Do you use Assigned Identify in NHibernate then?