How to add a constraint to an EF Code First table

Question

First, I'm not sure if I'm reinventing the wheel with regards to foreign keys here, but lets say I have a Patient table

PatientId
Name
Gender
Age
HospitalId

I want to make sure that when an object is inserted into the Patient table, that it won't insert a record with a HospitalId that doesn't exist in the Hospital table. Is there an efficient way of doing this? Or as I said above am I reinventing a wheel here?

Answer 1

Try this:

public class Patient
{
    public int PatientId {get;set;}
    public string Name {get;set;}
    public string Gender {get;set;}
    public int Age {get;set;}
    public int HospitalId {get;set;}

    //add this line of code
    public virtual Hospital Hospital {get;set;}
}

Also you can change Hospital class this way:

public class Hospital 
{
    //your code....
    //new property
    public virtual ICollection<Patient> Patients {get;set;}    
}