Unable to save Email property to sql in due to SQL Exception Error :"Null insert not allowed" except property is not null??(ORM-code first)

Question

I want to generate the email when an employee is created using properties (FirstName and LastName) from the base class:

public class Person
{
    public int Id { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public DateTime DOB { get; set; }
    public string Phone { get; set; }

}

 public class Employee : Person
{
    public Employee()
    {
        Packages = new List<Package>();

    }
    public string Email { get =>$"{FirstName[0]}.{LastName}@GTravel.com.au"; }

    public IEnumerable<Package> Packages { get; set; }
}

So the output should be something like: J.Smith@GTravel.com.au I then want to be able to save this employee into a sql database with Person as the Entity/Table and Employee as the discriminator.

using (var gtmsdb = new GTMSDbContext())
        {

            var newEmployee = new Employee
            {
                FirstName = "John",
                LastName = "Smith",
                DOB = new DateTime(1992, 09, 16),
                Phone = "03-1234-567"

            };
            gtmsdb.People.Add(newEmployee);
            gtmsdb.SaveChanges();

        }

Shows Employee in debugger with email created

When I run the code it creates the employee with the Email in the correct format and everything but when I try saving to the database it returns the error:

SqlException: Cannot insert the value NULL into column 'Email', table 'GTMSDatabase.dbo.People'; column does not allow nulls. INSERT fails.

I also tried saving the Email as a simple {get; set;} and then hard coded the email:

 public string Email { get; set; }


 var newEmployee = new Employee
            {
                FirstName = "John",
                LastName = "Smith",
                DOB = new DateTime(1992, 09, 16),
                Phone = "032166702",
                Email ="j.smith@gtravel"

            };
            gtmsdb.People.Add(newEmployee);
            gtmsdb.SaveChanges();

But that still returned the same error message. I also tested with other(new) properties that worked perfectly fine, deleted and retried the migrations, checked in my database for an error there but I am now unsure of the next step to take. There are no references to Email in my Context so is it something that I need to be initialising there?

Edit: I created another smaller scale project where I ran the exact same code and the email saved with no issues:

using (var db = new ETDbContext())
        {
            var newEmployee = new Employee
            {
                FirstName = "John",
                LastName = "Smith",
                DOB = new DateTime(1992, 09, 16),
                Phone = "032166702"

            };
            db.People.Add(newEmployee);
            var nc = new Customer
            {
                FirstName = "Jane",
                LastName = "Doe",
                DOB = new DateTime(1992, 09, 16),
                Phone = "032166702",
                Email = "customerEmail"
            };
            db.People.Add(nc);
            db.SaveChanges();

        }

I tried to add a Customer just to make sure everything worked but ran into the same problem! Anytime I would create an employee it would save no issues but with the customer it returned the same null reference error

Answer 1

Have you checked before it tries to save if the Email has been set?, If it goes null then the set isn't working, I will do something like below.

 var newEmployee = new Employee
        {
            FirstName = "John",
            LastName = "Smith",
            DOB = new DateTime(1992, 09, 16),
            Phone = "03-1234-567",
            Email = '';
        };
 newEmployee.Email = newEmployee.FirstName.Substring(0,1).ToLower() + 
 newEmployee.LastName.ToLower() +"@gtravel";