UdtTypeName and .NET data types in SQL

We are working on SQL 2008 for a new project with the intent to leverage the new data types, in this case especially the HIERARCHYID data type. One of the stored procedures we created had a parameter of type HIERARCHYID.

The code that calls the stored procedure was something like this.

SqlHierarchyId nodeValue = GetNodeValueFromSomewhere();
var cmd =new SqlCommand("usp_EnableNode");
cmd.CommandType = CommandType.StoredProcedure;
var  nodeParam = myCommand.Parameters.Add("@Node", SqlDbType.SqlHierarchyId);
nodeParam.Value = nodeValue; 
var enableParam = myCommand.Parameters.Add("@Enable",  SqlDbType.SqlBit);
enableParam.Value = true;
cmd.ExecuteNonQuery();

When running this code we were getting the error "UdtTypeName property must be set for UDT parameters." Since the HIERARCHYID data type is a .NET type in SQL 2008 and we had not played with .NET types in SQL 2005 yet, we scratched our heads for a few minutes.

We tried both:

nodeParam.UdtTypeName = typeof(SqlHierarchyId).Name; 

And

nodeParam.UdtTypeName = typeof(SqlHierarchyId).FullName; 

But the solution was much simpler:

nodeParam.UdtTypeName = "HierarchyId";

This should be needed for the new GEOMETRY and GEOGRAPHY data types as well. Maybe this helps someone else.