TIP: Managing SqlGeography class from C#

It took me some time to get this to work. The problem is that SqlGeography C# type, which corresponds to Geography SQL type, is considered an user-defined type (UDT) by the .net SQL library.

So, the proper way to insert or update a Geography field is something like this:

SqlGeography geo = // Get the coordinates from somewhere...

using (SqlCommand command = 
    new SqlCommand(@"UPDATE Points SET Point=@Point WHERE FeatureID='9999'", connection))
    command.Parameters.Add(new SqlParameter("@Point", geo) { UdtTypeName = "Geography" });
    command.ExecuteNonQuery();
}