Question

I need to add a record to a database using the Entity Framework. Since I’m brand new to using this syntax I am not sure how to properly write the code (Below is my best guess).

First, the agent must have their info inserted into the Agent table. This table produces a self-incrementing primary key known as a SymNumber. I then need to take that SymNumber and use it as a primary key for an insert into the AgentIdentification table.

I have run this code a couple of times, and I do not come up with an error, however since I am using a unit test to test the code I cannot tell for sure if the agent is being added properly. Secondly, I know for a fact that I am not correctly grabbing the SymNumber as generated by the Agent table after the first insert. The SymNumber is an int value in the Linq code set to 0, and this does not change during the AgentIdentification insert.

Any help would be greatly appreciated!

        AgentResourcesEntities _db = new AgentResourcesEntities();

        try
        {
            Agent agent = new Agent();
            agent.EntityType = "P";
            agent.FirstName = agentNewTraining.FirstName;
            agent.LastName = agentNewTraining.LastName;
            agent.LastChangeOperator = agentNewTraining.Requestor;
            agent.LastChangeDate = DateTime.Now;
            if (!String.IsNullOrEmpty(agentNewTraining.NameSuffix)) agent.NameSuffix = agentNewTraining.NameSuffix;

            _db.Agent.AddObject(agent);

            AgentIdentification agentIdentification = new AgentIdentification();
            agentIdentification.SymNumber = agent.SymNumber;
            agentIdentification.ReferenceType = "S";
            agentIdentification.DummyReference = 0;
            agentIdentification.LastChangeOperator = agentNewTraining.Requestor;
            agentIdentification.LastChangeDate = DateTime.Now;

            _db.AgentIdentification.AddObject(agentIdentification);

            return true;
        }
        catch (Exception)
        {
            return false;
        }

Answer 1

First you need to call

_db.SaveChanges();

to get your changed persisted.

But if you want also synchronize (get the new generated value) your agent.SymNumber you will need to call SaveChanges() right after adding it to context.

So the code will be like:

/// ...... ////
_db.Agent.AddObject(agent);
_db.SaveChanges();

AgentIdentification agentIdentification = new AgentIdentification();
agentIdentification.SymNumber = agent.SymNumber;  // sym number is now synchronized from DB
 ///...../////

_db.AgentIdentification.AddObject(agentIdentification);
_db.SaveChanges();

But if SymNumber is foreign key so the AgentIdentification has could have reference to some Agent instance, you can just tie those instances with that reference and would not need to call that additional SaveChanges() in the middle.