How to insert null value in Database through parameterized query

Question

I have a datetime datatype : dttm

Also the database field type is datatime

Now I am doing this:

if (dt         


        

Answer 1

Use DBNull.Value

if (dttm.HasValue)
{
    cmd.Parameters.AddWithValue("@dtb", dttm);
}
else
{
    cmd.Parameters.AddWithValue("@dtb", DBNull.Value)
}