Question

So, First of all. Code:
I’ve got a class:

public class Myobject
{
    public string Code { get; set; }
    public DateTime? StartDate { get; set; }
}

And this is part of very simple source:

MyObject mo = new MyObject();
mo.Code= "sth";
// NO action on StartDate property! 

    if (mo.StartDate.HasValue)
    {
        sc.Parameters.Add(new SqlParameter("@inStartDate", mo.StartDate.Value));
    }
    else
    {
        sc.Parameters.Add(new SqlParameter("@inStartDate", DBNull.Value));
    }

Simple ‘if’ – Sql Server 2008, throw an error – when gets null Datetime (it has to be DBNull.Value)
So I want to check it first, and then pass right value or DBNull.

My problem is – this ‘if’ always retruns true! Why!?

Also tried that:

if (mo.StartDate.Value == null)

but it always returns false. How come it is not a null? It was not even created..

So.. How to check if DateTime object was not assigned?

Answer 1

Try this:

if (mo.StartDate.GetValueOrDefault() != DateTime.MinValue) 
{
  // True - mo.StartDate has value
}
else
{
  // False - mo.StartDate doesn't have value
}