Intercepting ADD to detect if it is an ADD through a collection in Entity Framework 5 - entity-framework-5

Question

I have kinda 2 questions that can be answered separately.
Q#1
I am trying to save round trips to the database server.
Here's my algo:
Insert 2 entities (to get their IDs generated by the database)
Use the IDs returned to call a stored procedure passing it the IDs
The stored procedure takes the IDs and populates an adjacency list table which I am using to store a directed acyclic graph.
Currently I have a round-trip to the RDBMS for each parent-child relationship, plus one for the Insert of the entities.
I am known to do stuff like this:
public override int SaveChanges()
{
foreach (var entry in this.ChangeTracker.Entries().Where(e => e.State == System.Data.EntityState.Added).ToList())
{
if (entry.Entity is IRobot)
{
entry.Reference("Owner").CurrentValue = skyNet;
}
}
return base.SaveChanges();
}
So I was wondering if there was a way that I can detect an EntityState.Added for an "ADD" that was done similar to the following code:
var robot = new Robot();
skyNet.Robots.Add(robot);
db.Add(skyNet);
db.SaveChanges();
So that I can do something like this: (Note that this is psuedocode)
public override int SaveChanges()
{
foreach (var entry in this.ChangeTracker.Entries().Where(e => e.State == EntityState.**AddedToCollection**).ToList())
{
db.Relate(parent: skyNet, child: entry.Entity);
}
return base.SaveChanges();
}
Q#2
Is there anyway to call a stored procedure as part of the same "trip" to the database after calling a SaveChanges()?

Answer 1

Question 1
You can detect the state of an entity by
db.Entry(robot).State
After the line
skyNet.Robots.Add(robot);
the EntityState of robot will be Added. However, in your pseudocode it is not clear where the skyNet variable comes from. If you add the skyNet as you do in your code snippet you could do:
foreach( var skyNet in ChangeTracker.Entries()
.Where(e => e.State == EntityState.Added)
.Select (e => e.Entity)
.OfType<SkyNet>())
{
foreach(var robot in skyNet.Robots
.Where(r => db.Entry(r).State == EntityState.Added))
{
db.Relate(parent: skyNet, child: robot);
}
}
Question 2
You can't call a stored procedure in one roundtrip, that would require something like NHibernate's multi query. But, you can wrap SaveChanges and a stored procedure call in one transaction (which I think is what you mean) by using TransactionScope:
using (TransactionScope scope = new TransactionScope())
{
// stored procedure call here.
db.SaveChanges();
scope.Complete();
}