[c#] How to set null to a GUID property

I have an object of type Employee which has a Guid property. I know if I want to set to null I must to define my type property as nullable Nullable<Guid> prop or Guid? prop.

But in my case I'm not able to change the type of the prop, so it will remains as Guid type and my colleague and I we don't want to use the Guid.Empty.

Is there a way to set my property as null or string.empty in order to restablish the field in the database as null.

I have a mechanism to transform from string.empty to null but I will change many things if the would change to accept a empty guid to null.

Any help please!

you can make guid variable to accept null first using ? operator then you use Guid.Empty or typecast it to null using (Guid?)null;

eg:

 Guid? id = Guid.Empty;

or

 Guid? id =  (Guid?)null;

I think this is the correct way:

Guid filed = Guid.Empty;

Since "Guid" is not nullable, use "Guid.Empty" as default value.

extrac Guid values from database functions:

    #region GUID

    public static Guid GGuid(SqlDataReader reader, string field)
    {
        try
        {
            return reader[field] == DBNull.Value ? Guid.Empty : (Guid)reader[field];
        }
        catch { return Guid.Empty; }
    }

    public static Guid GGuid(SqlDataReader reader, int ordinal = 0)
    {
        try
        {
            return reader[ordinal] == DBNull.Value ? Guid.Empty : (Guid)reader[ordinal];
        }
        catch { return Guid.Empty; }
    }

    public static Guid? NGuid(SqlDataReader reader, string field)
    {
        try
        {
            if (reader[field] == DBNull.Value) return (Guid?)null; else return (Guid)reader[field];
        }
        catch { return (Guid?)null; }
    }

    public static Guid? NGuid(SqlDataReader reader, int ordinal = 0)
    {
        try
        {
            if (reader[ordinal] == DBNull.Value) return (Guid?)null; else return (Guid)reader[ordinal];
        }
        catch { return (Guid?)null; }
    }

    #endregion

Guid? myGuidVar = (Guid?)null;

It could be. Unnecessary casting not required.

Guid? myGuidVar = null;

Choose your poison - if you can't change the type of the property to be nullable then you're going to have to use a "magic" value to represent NULL. Guid.Empty seems as good as any unless you have some specific reason for not wanting to use it. A second choice would be Guid.Parse("ffffffff-ffff-ffff-ffff-ffffffffffff") but that's a lot uglier IMHO.

You can use typeof(Guid), "00000000-0000-0000-0000-000000000000" for DefaultValue of the property.